85xx io out functions need sync after write.

This fixes the mc146818 rtc_read/write functions for 85xx.

Signed-off-by: Ed Swarthout <Ed.Swarthout@freescale.com>
diff --git a/cpu/mpc85xx/start.S b/cpu/mpc85xx/start.S
index 2c98c2a..5d65190 100644
--- a/cpu/mpc85xx/start.S
+++ b/cpu/mpc85xx/start.S
@@ -701,6 +701,7 @@
 	.globl	out8
 out8:
 	stb	r4,0x0000(r3)
+	sync
 	blr
 
 /*------------------------------------------------------------------------------- */
@@ -710,6 +711,7 @@
 	.globl	out16
 out16:
 	sth	r4,0x0000(r3)
+	sync
 	blr
 
 /*------------------------------------------------------------------------------- */
@@ -719,6 +721,7 @@
 	.globl	out16r
 out16r:
 	sthbrx	r4,r0,r3
+	sync
 	blr
 
 /*------------------------------------------------------------------------------- */
@@ -728,6 +731,7 @@
 	.globl	out32
 out32:
 	stw	r4,0x0000(r3)
+	sync
 	blr
 
 /*------------------------------------------------------------------------------- */
@@ -737,6 +741,7 @@
 	.globl	out32r
 out32r:
 	stwbrx	r4,r0,r3
+	sync
 	blr
 
 /*------------------------------------------------------------------------------- */