Rather than each driver test MMC_DEBUG itself, and define DEBUG,
pass it in via the makefile instead.

Fix drivers to use pr_debug() where appropriate, and avoid defining
a DEBUG() macro.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Adds OMAP MMC driver.
Signed-off-by: NJuha Yrjl <juha.yrjola@nokia.com>
Signed-off-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NCarlos Aguiar <carlos.aguiar@indt.org.br>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>