ANDROID: mmc: block: rename rqc to new_req

Upstream commit acd8dbd6 ("mmc: block: rename rqc and req")
renamed "rqc" to "new_req". No functional changes.

Fixes: Change-Id: I342bfbd8b85f9b790e3f0e1e4e51a900ae07e05d
       ("ANDROID: mmc: Add CONFIG_MMC_SIMULATE_MAX_SPEED")
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>