mmc: core: Rename cmd_timeout_ms to busy_timeout

To better reflect that the cmd_timeout_ms is directly related to the
busy detection timeout, let's rename it.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Chris Ball <chris@printf.net>

diff --cc drivers/mmc/core/core.c
Simple merge

diff --cc drivers/mmc/core/mmc_ops.c
Simple merge

diff --cc drivers/mmc/host/sdhci.c
Simple merge

diff --cc include/linux/mmc/core.h
Simple merge