sk98lin: fix compile warnings

Fix warnings:
skge.c: In function 'BoardInitMem':
skge.c:1389: warning: dereferencing type-punned pointer will break strict-aliasing rules
skge.c:1390: warning: dereferencing type-punned pointer will break strict-aliasing rules
skge.c:1391: warning: dereferencing type-punned pointer will break strict-aliasing rules
skgesirq.c: In function 'SkGePortCheckUpXmac':
skgesirq.c:1301: warning: dereferencing type-punned pointer will break strict-aliasing rules
skgesirq.c:1301: warning: dereferencing type-punned pointer will break strict-aliasing rules
skgesirq.c:1398: warning: dereferencing type-punned pointer will break strict-aliasing rules
skgesirq.c:1398: warning: dereferencing type-punned pointer will break strict-aliasing rules
skrlmt.c: In function 'SkRlmtInit':
skrlmt.c:661: warning: dereferencing type-punned pointer will break strict-aliasing rules
skxmac2.c: In function 'SkMacPromiscMode':
skxmac2.c:753: warning: dereferencing type-punned pointer will break strict-aliasing rules
skxmac2.c:753: warning: dereferencing type-punned pointer will break strict-aliasing rules
skxmac2.c: In function 'SkMacHashing':
skxmac2.c:803: warning: dereferencing type-punned pointer will break strict-aliasing rules
skxmac2.c:803: warning: dereferencing type-punned pointer will break strict-aliasing rules
skxmac2.c: In function 'SkMacFlushTxFifo':
skxmac2.c:1115: warning: dereferencing type-punned pointer will break strict-aliasing rules
skxmac2.c:1115: warning: dereferencing type-punned pointer will break strict-aliasing rules
skxmac2.c: In function 'SkMacFlushRxFifo':
skxmac2.c:1145: warning: dereferencing type-punned pointer will break strict-aliasing rules
skxmac2.c:1145: warning: dereferencing type-punned pointer will break strict-aliasing rules
skxmac2.c: In function 'SkXmInitPauseMd':
skxmac2.c:1987: warning: dereferencing type-punned pointer will break strict-aliasing rules
skxmac2.c:1987: warning: dereferencing type-punned pointer will break strict-aliasing rules
skxmac2.c: In function 'SkXmOverflowStatus':
skxmac2.c:4236: warning: dereferencing type-punned pointer will break strict-aliasing rules
skxmac2.c:4236: warning: dereferencing type-punned pointer will break strict-aliasing rules
skxmac2.c:4242: warning: dereferencing type-punned pointer will break strict-aliasing rules
skxmac2.c:4242: warning: dereferencing type-punned pointer will break strict-aliasing rules

Signed-off-by: Wolfgang Denk <wd@denx.de>
Cc: Ben Warren <biggerbadderben@gmail.com>
diff --git a/drivers/net/sk98lin/skgesirq.c b/drivers/net/sk98lin/skgesirq.c
index 106fe48..53229d2 100644
--- a/drivers/net/sk98lin/skgesirq.c
+++ b/drivers/net/sk98lin/skgesirq.c
@@ -1266,6 +1266,7 @@
 	SK_GEPORT	*pPrt;		/* GIni Port struct pointer */
 	int			Done;
 	SK_U32		GpReg;		/* General Purpose register value */
+	SK_U32		*pGpReg;	/* Pointer to -- " -- */
 	SK_U16		Isrc;		/* Interrupt source register */
 	SK_U16		IsrcSum;	/* Interrupt source register sum */
 	SK_U16		LpAb;		/* Link Partner Ability */
@@ -1274,6 +1275,8 @@
 	SK_BOOL		AutoNeg;	/* Is Auto-negotiation used ? */
 	SK_U8		NextMode;	/* Next AutoSensing Mode */
 
+	pGpReg = &GpReg;
+
 	pPrt = &pAC->GIni.GP[Port];
 
 	if (pPrt->PHWLinkUp) {
@@ -1298,7 +1301,7 @@
 
 	if (pPrt->PLinkBroken) {
 		/* Link was broken */
-		XM_IN32(IoC, Port, XM_GP_PORT, &GpReg);
+		XM_IN32(IoC, Port, XM_GP_PORT, pGpReg);
 
 		if ((GpReg & XM_GP_INP_ASS) == 0) {
 			/* The Link is in sync */
@@ -1395,7 +1398,7 @@
 	 * here we usually can check whether the link is in sync and
 	 * auto-negotiation is done.
 	 */
-	XM_IN32(IoC, Port, XM_GP_PORT, &GpReg);
+	XM_IN32(IoC, Port, XM_GP_PORT, pGpReg);
 	XM_IN16(IoC, Port, XM_ISRC, &Isrc);
 	IsrcSum |= Isrc;