omap mmc: Remove broken MMC init code

Most of the omap1 MMC boards got broken by an earlier patch
138ab9f8

. If you look closely,
the MMC init funtions are pretty much just stubs.

Remove broken init code to make room for cleaner MMC init code.

Cc: Pierre Ossman <drzeus-mmc@drzeus.cx>
Signed-off-by: Tony Lindgren <tony@atomide.com>