mmc: mtk-sd: Demote msdc_recheck_sdio_irq() function header

No other function in the file is documented using kerneldoc and no
effort to document the function arguments have been made.  It's a
bit of an oddity to say the least.  Let's downgrade it from
kerneldoc to a standard comment block instead.

Fixes the following W=1 kernel build warning:

 drivers/mmc/host/mtk-sd.c:1030: warning: Function parameter or member 'host' not described in 'msdc_recheck_sdio_irq'

Cc: Chaotian Jing <chaotian.jing@mediatek.com>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Cc: linux-mediatek@lists.infradead.org
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com>
Link: https://lore.kernel.org/r/20200701124702.908713-6-lee.jones@linaro.orgSigned-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/mmc/host/mtk-sd.c

@@ -1018,13 +1018,12 @@ static int msdc_auto_cmd_done(struct msdc_host *host, int events,
 	return cmd->error;
 }
 
-/**
+/*
  * msdc_recheck_sdio_irq - recheck whether the SDIO irq is lost
  *
  * Host controller may lost interrupt in some special case.
  * Add SDIO irq recheck mechanism to make sure all interrupts
  * can be processed immediately
- *
  */
 static void msdc_recheck_sdio_irq(struct msdc_host *host)
 {