mpc83xx: Normalize BR/OR option lines

All BR/OR option lines should have the same layout to make them easier
to migrate to Kconfig. This includes using the same option macros
everywhere.

The normalize the lines,
* replace function macros with their results, and
* replace hardcoded hex values with standard macros

Signed-off-by: Mario Six <mario.six@gdsys.cc>
diff --git a/include/configs/vme8349.h b/include/configs/vme8349.h
index ed02661..76821e7 100644
--- a/include/configs/vme8349.h
+++ b/include/configs/vme8349.h
@@ -74,7 +74,7 @@
 					 BR_MS_GPCM |	/*  MSEL = GPCM */ \
 					 BR_V)		/* valid */
 
-#define CONFIG_SYS_OR0_PRELIM		(MEG_TO_AM(CONFIG_SYS_FLASH_SIZE) \
+#define CONFIG_SYS_OR0_PRELIM		(OR_AM_128MB \
 					| OR_GPCM_XAM \
 					| OR_GPCM_CSNT \
 					| OR_GPCM_ACS_DIV2 \