Revert "PowerPC: Add support for -msingle-pic-base"

This reverts commit 39768f7715ed637ef02f49fc7de664cc1aaf14b3.

Reson: it breaks a number of boards with embedded environment as the
code size grows in some places.
diff --git a/arch/powerpc/cpu/mpc5xxx/start.S b/arch/powerpc/cpu/mpc5xxx/start.S
index 0a05361..192aa50 100644
--- a/arch/powerpc/cpu/mpc5xxx/start.S
+++ b/arch/powerpc/cpu/mpc5xxx/start.S
@@ -160,11 +160,7 @@
 	/*--------------------------------------------------------------*/
 
 	GET_GOT			/* initialize GOT access		*/
-#if defined(__pic__) && __pic__ == 1
-	/* Needed for upcoming -msingle-pic-base */
-	bl	_GLOBAL_OFFSET_TABLE_@local-4
-	mflr	r30
-#endif
+
 	/* r3: IMMR */
 	bl	cpu_init_f	/* run low-level CPU init code (in Flash)*/
 
@@ -553,11 +549,6 @@
 	mr	r10, r5		/* Save copy of Destination Address	*/
 
 	GET_GOT
-#if defined(__pic__) && __pic__ == 1
-	/* Needed for upcoming -msingle-pic-base */
-	bl	_GLOBAL_OFFSET_TABLE_@local-4
-	mflr	r30
-#endif
 	mr	r3,  r5				/* Destination Address	*/
 	lis	r4, CONFIG_SYS_MONITOR_BASE@h		/* Source      Address	*/
 	ori	r4, r4, CONFIG_SYS_MONITOR_BASE@l