Add initial support for Freescale mx51evk board

The patch adds initial support for the Freescale mx51evk board.
Network (FEC) and SD controller (fsl_esdhc) are supported.

Signed-off-by: Stefano Babic <sbabic@denx.de>
Signed-off-by: Fred Fan <fanyefeng@gmail.com>
diff --git a/Makefile b/Makefile
index 16b549c..ca399db 100644
--- a/Makefile
+++ b/Makefile
@@ -3300,6 +3300,9 @@
 	fi
 	@$(MKCONFIG) -a mx31pdk arm arm1136 mx31pdk freescale mx31
 
+mx51evk_config	: unconfig
+	@$(MKCONFIG) $(@:_config=) arm arm_cortexa8 mx51evk freescale mx51
+
 omap2420h4_config	: unconfig
 	@$(MKCONFIG) $(@:_config=) arm arm1136 omap2420h4 ti omap24xx
 
@@ -3771,6 +3774,7 @@
 		$(obj)cscope.* $(obj)*.*~
 	@rm -f $(obj)u-boot $(obj)u-boot.map $(obj)u-boot.hex $(ALL)
 	@rm -f $(obj)u-boot.kwb
+	@rm -f $(obj)u-boot.imx
 	@rm -f $(obj)tools/{env/crc32.c,inca-swap-bytes}
 	@rm -f $(obj)cpu/mpc824x/bedbug_603e.c
 	@rm -f $(obj)include/asm/proc $(obj)include/asm/arch $(obj)include/asm