mmc: dw_mmc: gather each reset code into functions

There are three resets in CTRL register.  FIFO reset is especially used
in several points with the same routine. It could be replaced with one
function and the others may be applied similarly if needed.  So,
mci_wait_reset() is modified to allow various bit field of reset.

Signed-off-by: Seungwon Jeon <tgih.jun@samsung.com>
Tested-by: Alim Akhtar <alim.akhtar@samsung.com>
Signed-off-by: Chris Ball <cjb@laptop.org>