mmc: rtsx: remove driving adjustment

Several new models of readers use different way to select driving
capability (a necessary adjustment along with voltage change). Removing
this from device-independent rtsx_pci_sdmmc module. It will be implemented
in device-depend calls encapsulated by rtsx_pci_switch_output_voltage().

Signed-off-by: Roger Tseng <rogerable@realtek.com>
Reviewed-by: Wei WANG <wei_wang@realsil.com.cn>
Signed-off-by: Chris Ball <cjb@laptop.org>

drivers/mmc/host/rtsx_pci_sdmmc.c

@@ -1083,11 +1083,6 @@ static int sdmmc_switch_voltage(struct mmc_host *mmc, struct mmc_ios *ios)
 		voltage = OUTPUT_1V8;
 
 	if (voltage == OUTPUT_1V8) {
-		err = rtsx_pci_write_register(pcr,
-				SD30_DRIVE_SEL, 0x07, DRIVER_TYPE_B);
-		if (err < 0)
-			goto out;
-
 		err = sd_wait_voltage_stable_1(host);
 		if (err < 0)
 			goto out;