mmc: sdhci-msm: Demote faux kerneldoc header down to basic comment block

__sdhci_msm_set_clock()'s function header is the only one in
kerneldoc format.  Which seems odd as it's not part of an
external API and isn't referenced anywhere else.  Seeing as
there has also been no attempt to describe the expected
function arguments either, we're going to assume that this is
not actually a bona fide kerneldoc use-case.

Fixes the following W=1 kernel build warnings:

 drivers/mmc/host/sdhci-msm.c:1595: warning: Function parameter or member 'host' not described in '__sdhci_msm_set_clock'
 drivers/mmc/host/sdhci-msm.c:1595: warning: Function parameter or member 'clock' not described in '__sdhci_msm_set_clock'

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andy Gross <agross@kernel.org>
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: linux-arm-msm@vger.kernel.org
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20200701124702.908713-14-lee.jones@linaro.orgSigned-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/mmc/host/sdhci-msm.c

@@ -1702,7 +1702,7 @@ static unsigned int sdhci_msm_get_min_clock(struct sdhci_host *host)
 	return SDHCI_MSM_MIN_CLOCK;
 }
 
-/**
+/*
  * __sdhci_msm_set_clock - sdhci_msm clock control.
  *
  * Description: