env_mmc: Fix crashing bug encountered after enabling ARM relocation

The crash was occuring in env_relocate because it was being called prior
to mmc_initialize.  This patch moves the MMC initialization earlier in
the init process.

This patch also cleans up the env_relocate_spec code in env_mmc.c

Signed-off-by: Steve Sakoman <steve.sakoman@linaro.org>
Acked-by: Stefano Babic <sbabic@denx.de>
diff --git a/arch/arm/lib/board.c b/arch/arm/lib/board.c
index 22bd2c9..108e6c4 100644
--- a/arch/arm/lib/board.c
+++ b/arch/arm/lib/board.c
@@ -770,6 +770,11 @@
 	onenand_init();
 #endif
 
+#ifdef CONFIG_GENERIC_MMC
+       puts("MMC:   ");
+       mmc_initialize(bd);
+#endif
+
 #ifdef CONFIG_HAS_DATAFLASH
 	AT91F_DataflashInit();
 	dataflash_print_info();
@@ -835,11 +840,6 @@
 	board_late_init ();
 #endif
 
-#ifdef CONFIG_GENERIC_MMC
-	puts ("MMC:   ");
-	mmc_initialize (gd->bd);
-#endif
-
 #ifdef CONFIG_BITBANGMII
 	bb_miiphy_init();
 #endif