mmc: remove MMC_CAP2_NO_MULTI_READ flags

Now, mmc framework uses multi_io_quirk
for I/O HW bug workaround.
MMC_CAP2_NO_MULTI_READ flag is no longer needed

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>