arm64: dts: qcom: sc7180: Update reg names for SDHC

Remove the redundant _mem suffix for SDHC reg names.

For SDcard instance, no need supply reg names since hc reg map
is accessed with index. So remove reg names for SDcard.

Signed-off-by: Veerabhadrarao Badiganti <vbadigan@codeaurora.org>
Link: https://lore.kernel.org/r/1583946863-24308-2-git-send-email-vbadigan@codeaurora.org


Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>