uboot-imx

Fix building for mx51evk board

Fix:
mx51evk.c:206:6: error: conflicting types for 'board_ehci_hcd_init'
/u-boot/include/usb/ehci-fsl.h:254:5: note: previous declaration of
'board_ehci_hcd_init' was here

We also fix board_ehci_hcd_init() for mx53loco board.
Building for mx53loco worked since <usb/ehci-fsl.h> is
not included here.

Signed-off-by: Anatolij Gustschin <agust@denx.de>