ppc4xx: Complete remove bogus dflush()

Since the current dflush() implementation is know to have some problems
(as seem on lwmon5 ECC init) this patch removes it completely and replaces
it by using clean_dcache_range().

Tested on Katmai with ECC DIMM.

Signed-off-by: Stefan Roese <sr@denx.de>
diff --git a/board/netstal/hcu5/sdram.c b/board/netstal/hcu5/sdram.c
index 0b16b505..6b1b53a 100644
--- a/board/netstal/hcu5/sdram.c
+++ b/board/netstal/hcu5/sdram.c
@@ -34,11 +34,11 @@
 #include <asm/processor.h>
 #include <asm/io.h>
 #include <asm/mmu.h>
+#include <asm/cache.h>
 #include <ppc440.h>
 
 void hcu_led_set(u32 value);
 void dcbz_area(u32 start_address, u32 num_bytes);
-void dflush(void);
 
 #define DDR_DCR_BASE 0x10
 #define ddrcfga  (DDR_DCR_BASE+0x0)   /* DDR configuration address reg */
@@ -185,14 +185,14 @@
 #endif
 
 	sync();
-	eieio();
 
 	puts(str);
 
 	/* ECC bit set method for cached memory */
 	/* Fast method, no noticeable delay */
 	dcbz_area(start_address, num_bytes);
-	dflush();
+	/* Write modified dcache lines back to memory */
+	clean_dcache_range(start_address, start_address + num_bytes);
 	blank_string(strlen(str));
 
 	/* Clear error status */