ARC: [axs101] STAR 9000799830: Fix SD cards support

As DW Mobile Storage databook says it's required to use "Hold Register"
if card is enumerated in SDR12 or SDR25 modes.
It means we need to act in the same way as in Altera's Socfpga
implementation - set "use hold reg" bit in commad.

Note that for upstream proper solution would be to remove
dw_mci_pltfm_prepare_command() at all and set the bit right in
dw_mci_prepare_command() for all platforms.

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>