qcom_defconfig: Disable MMC HS200 mode support

qcom_defconfig: Disable MMC HS200 mode support

Currently the msm_sdhci doesn't yet support DLL configurations which are
required to enable bus speeds greater that 100MHz. So disable HS200 mode
support as of now as it requires bus speeds of 200MHz.

This should fix eMMC issues reported on RB1/RB2 although it should fix
issues for all Qcom platforms but it's not seen there as mostly SD cards
available don't support HS200 mode. The SD cards usually works in high
speed mode whose performance remains unaffected by this change. It only
affects RB1/RB2 as eMMC flash on these support HS200 mode but the U-Boot
driver currently is incapable of supporting that.

Reviewed-by: Caleb Connolly <caleb.connolly@linaro.org>
Signed-off-by: Sumit Garg <sumit.garg@oss.qualcomm.com>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://lore.kernel.org/r/20250410080027.208674-2-sumit.garg@kernel.org
Signed-off-by: Caleb Connolly <caleb.connolly@linaro.org>