This change helps to choose msize, rx_watermark and tx_watermark
depending on block size for IDMAC mode.  For SDIO block size can be
variable, so if these values are set incorrectly, card clock may stop.
Signed-off-by: NSeungwon Jeon <tgih.jun@samsung.com>
Tested-by: NAlim Akhtar <alim.akhtar@samsung.com>
Signed-off-by: NChris Ball <cjb@laptop.org>