am335x_evm: Enable CONFIG_CMD_BOOTZ

With v3.9 and later of the Linux Kernel defaulting to multi-platform
images with omap2plus_defconfig, uImage isn't builtable anymore by
default.  Add CONFIG_CMD_BOOTZ so that we can still boot something the
kernel spits out.

Signed-off-by: Tom Rini <trini@ti.com>
Acked-by: Peter Korsgaard <jacmet@sunsite.dk>

include/configs/am335x_evm.h

@@ -35,6 +35,7 @@
 #define CONFIG_MACH_TYPE		MACH_TYPE_TIAM335EVM
 
 #define CONFIG_OF_LIBFDT
+#define CONFIG_CMD_BOOTZ
 #define CONFIG_CMDLINE_TAG		/* enable passing of ATAGs */
 #define CONFIG_SETUP_MEMORY_TAGS
 #define CONFIG_INITRD_TAG