ARM: mach-meson: select MMC_PWRSEQ config

Before time, PWRSEQ is selected since below commit.
commit 262d3436 ("board: amlogic: select PWRSEQ for all amlogic platform")
Select MMC_PWRSEQ config because of introducing CONFIG_MMC_PWRSEQ for
only eMMC module.

Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>