The commit above made quirks with an OEMID fail to be applied, as they
were checking card->cid.oemid for the full 16 bits defined in MMC_FIXUP
macros but the field would only contain the bottom 8 bits.
eMMC v5.1A might have bogus values in OEMID's higher bits so another fix
will be made, but it has been decided to revert this until that is ready.