mmc: omap_hsmmc: enable proper CMD(DAT) lines reset procedure for am43xx

The CMD(DAT) lines reset procedure described in the OMAP4(AM335x,
OMAP5, DRA7xx) TRMs is also necessary for AM43XX. Enable it in the
driver.

Cc: Pantelis Antoniou <panto@antoniou-consulting.com>
Cc: Igor Grinberg <grinberg@compulab.co.il>
Cc: Albert Aribaud <albert.u.boot@aribaud.net>
Signed-off-by: Nikita Kiryanov <nikita@compulab.co.il>