As a first step in removing code for MMC_CLKGATE, MIPS db1235 defconfig
which is the only current user, shall move away from this option.
The mmc host drivers au1xmmc and jz4740_mmc, which are used on MIPS
don't support clock gating through MMC_CLKGATE, thus removing the
config option will have no effect on power save - clock gating wise.