mmc: Access mode validation for eMMC cards > 2 GiB

This patch provides handling of the two way handshake when SEND_OP_COND
(CMD1) is send to mmc card. It is necessary to inform eMMC card if the
host can work with high capacity cards (Jedec JESD84-A441, point 7.4.3).

The extra flag MMC_MODE_HC (high capacity) is added to indicate if the
host is capable of handling the high capacity eMMC cards.

Since this change is added to the generic mmc framework, then it requires
other boards to indicate if their mmc controllers can handle high capacity
cards. As it is now - the old behaviour of the framework is preserved.

Signed-off-by: Lukasz Majewski <l.majewski@samsung.com>
Signed-off-by: Andy Fleming <afleming@freescale.com>