Since commit 30832ab5 ("mmc: sdhci: Always pass clock request value
zero to set_clock host op") was merged, esdhc_set_clock starts hitting
"if (clock == 0)" where ESDHC_SYSTEM_CONTROL has been operated.  This
causes SDHCI card-detection function being broken.  Fix the regression
by moving "if (clock == 0)" above ESDHC_SYSTEM_CONTROL operation.
Signed-off-by: NShawn Guo <shawn.guo@linaro.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: NChris Ball <cjb@laptop.org>