mmc: add support for Phytium MMC

phytium inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I8B6VC


CVE: NA

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Phytium sdci supports SD card slots on Soc FT2000/4 and D2000.
Phytium mci plat and pci is based on Phytium mci,
support Multimedia Card Interface such as SD, MMC.

Signed-off-by: Malloy Liu <liuqi1610@phytium.com.cn>