mmc: omap: remove unnecessary #if 0's

In commit 3451c067 (mmc: omap: add DMA engine support), some #if 0's
were used to comment out parts of the code.  This has been in the code
for over a year and are not needed anymore (and the commented-out code
doesn't even compile).  Remove them.

Signed-off-by: Luciano Coelho <coelho@ti.com>
Signed-off-by: Chris Ball <cjb@laptop.org>