mx51evk: Remove unused get_board_rev function

No board information is passed for MX51EVK, so remove get_board_rev function.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
diff --git a/board/freescale/mx51evk/mx51evk.c b/board/freescale/mx51evk/mx51evk.c
index afb1c30..37e6e4d 100644
--- a/board/freescale/mx51evk/mx51evk.c
+++ b/board/freescale/mx51evk/mx51evk.c
@@ -38,8 +38,6 @@
 
 DECLARE_GLOBAL_DATA_PTR;
 
-static u32 system_rev;
-
 #ifdef CONFIG_FSL_ESDHC
 struct fsl_esdhc_cfg esdhc_cfg[2] = {
 	{MMC_SDHC1_BASE_ADDR, 1},
@@ -47,11 +45,6 @@
 };
 #endif
 
-u32 get_board_rev(void)
-{
-	return system_rev;
-}
-
 int dram_init(void)
 {
 	/* dram_init must store complete ramsize in gd->ram_size */
@@ -404,8 +397,6 @@
 
 int board_init(void)
 {
-	system_rev = get_cpu_rev();
-
 	/* address of boot parameters */
 	gd->bd->bi_boot_params = PHYS_SDRAM_1 + 0x100;
 
diff --git a/include/configs/mx51evk.h b/include/configs/mx51evk.h
index 85229d6..7c7544f 100644
--- a/include/configs/mx51evk.h
+++ b/include/configs/mx51evk.h
@@ -42,7 +42,6 @@
  */
 
 #define CONFIG_CMDLINE_TAG			/* enable passing of ATAGs */
-#define CONFIG_REVISION_TAG
 #define CONFIG_SETUP_MEMORY_TAGS
 #define CONFIG_INITRD_TAG