u-boot-imx: Remove Wandboard patch as it is now supported by mainline

The U-Boot 2013.04 provides Wandboard support so we don't need to keep
the old U-Boot around. It has been some time we're using the mainline
code by default for the Wandboard Solo and Dual without any reported
issues, so time to clean it.

Change-Id: I6139d8371ac5404abf65f7d55f2fbd703d52c1b8
Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>
m28evk: Add DENX M28EVK board support

Change-Id: I60012955c249d0a22726ef5127dc1cfbc5cfdd50
Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>