kernel-modules: Fix storage module selection for sdhci/mmc/ahci

kernel-modules: Fix storage module selection for sdhci/mmc/ahci

Currently the block driver detection for generic initrd doesn't include
the SD/MMC drivers so we fail to boot generic images on any device using
those platforms as boot devices when using a generic initrd. Add logic
to detect those modules. This primarily fixes embedded ARM devices but
also likely intel tablets/dev boards and enterprise hypervisors that
have the ability to boot from SD.

Also the ahci_init_controller misses a number of drivers that use the
libahci_platform module for the init so this fixes some missing achi
moduless too.

Finally it cleans up the ARM storage module hacks that the above now
deals with in a more generic manner.

Signed-off-by: <pbrobinson@gmail.com>