fix(plat/rcar3): fix eMMC boot support for R-Car D3
fix(plat/rcar3): fix eMMC boot support for R-Car D3

Fix to support of booting from eMMC (50MHz x 8) on
Draak board for R-Car D3.

Signed-off-by: Hideyuki Nitta <157a8d8ef8f394e865e6e7e05394892c6ab1e8cd@hitachi.com>
Signed-off-by: Toshiyuki Ogasahara <400c4e7a7839959b6b07a73f04007ccb4fab1369@hitachi.com>
Signed-off-by: Yoshifumi Hosoya <d86d911fdf74bc568916e51d62d67d57b0acd5dd@renesas.com>
Change-Id: I0ab2b5c7f8075acbf5f4a69694fb535dddc1a4c8

achingupta/arm-trusted-firmware,achingupta/arm-trusted-firmware