arch: mvebu: Disable by default unused peripherals in SPL

SPL on mvebu loads proper U-Boot from custom Marvell kwbimage format and
therefore support for other binary formats is not required to be present in
SPL. Boot source of proper U-Boot is defined by compile time options and
therefore it is not required to enable all possible and unused peripherals
in SPL by default.

This change decrease size of SPL binaries.

Signed-off-by: Pali Rohár <pali@kernel.org>
Reviewed-by: Stefan Roese <sr@denx.de>