uboot-phytec

arm: socfpga: imply SPL options instead of select

For a small SPL, it should be possible to build without SPI(-flash) drivers
or wihout MMC drivers.

For this to work, we have to change from 'select'ing options to 'imply'ing
them.

With this change, I can have SPL trimmed to my hard-wired starting method
(SPI-NOR or MMC) while still including all drivers in U-Boot.

Signed-off-by: Simon Goldschmidt <simon.k.r.goldschmidt@gmail.com>