mmc: host: sdhci-pci: Add Genesys Logic GL975x support

Add support for the GL9750 and GL9755 chipsets.

Enable v4 mode and wait 5ms after set 1.8V signal enable for GL9750/
GL9755. Fix the value of SDHCI_MAX_CURRENT register and use the vendor
tuning flow for GL9750.

Co-developed-by: Michael K Johnson <johnsonm@danlj.org>
Signed-off-by: Michael K Johnson <johnsonm@danlj.org>
Signed-off-by: Ben Chuang <ben.chuang@genesyslogic.com.tw>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
index 3a52f57..49ea02c 100644
--- a/drivers/mmc/host/Kconfig
+++ b/drivers/mmc/host/Kconfig
@@ -94,6 +94,7 @@
 	depends on MMC_SDHCI && PCI
 	select MMC_CQHCI
 	select IOSF_MBI if X86
+	select MMC_SDHCI_IO_ACCESSORS
 	help
 	  This selects the PCI Secure Digital Host Controller Interface.
 	  Most controllers found today are PCI devices.