mmc: mmci: Add Qualcomm specific register defines.

This patch adds a Qualcomm SD Card controller specific register variations
to header file. Qualcomm SDCC controller is pl180, with slight changes in
the register layout from standard pl180 register set.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>