mmc: dw_mmc: set the card_width bit per card.

This patch sets the card_width bit of CTYPE for the corresponding card.

CTYPE[31] and CTYPE[16] correspond respectively to card[15] and card[0]
for 8-bit mode. And CTYPE[15] and CTYPE[0] correspond respectively to
card[15] and CTYPE[0] for 1-bit or 4-bit mode.

Signed-off-by: Seungwon Jeon <tgih.jun@samsung.com>
Acked-by: Will Newton <will.newton@imgtec.com>
Signed-off-by: Chris Ball <cjb@laptop.org>