mmc: sdhci-uhs2: add pre-detect_init hook

This "pre" hook for detect_init(), uhs2_pre_detect_init, will be required
to enable UHS-II support, at least, on GL9755.

Signed-off-by: Ben Chuang <ben.chuang@genesyslogic.com.tw>
Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Message-ID: <20241018105333.4569-14-victorshihgli@gmail.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>