Kerneldoc expects arg descriptions to be in the format '@.*: '.  If either
the '@' or the ':' is omitted then kerneldoc complains that the description
is missing.  Add the missing ':' here and provide a new description for
'value'.

Fixes the following kernel build W=1 warnings:

 drivers/mmc/host/sdhci-of-arasan.c:1394: warning: Function parameter or member 'host' not described in 'sdhci_arasan_update_support64b'
 drivers/mmc/host/sdhci-of-arasan.c:1394: warning: Function parameter or member 'value' not described in 'sdhci_arasan_update_support64b'
 drivers/mmc/host/sdhci-msm.c:1887:6: warning: no previous prototype for ‘sdhci_msm_dump_vendor_regs’ [-Wmissing-prototypes]

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Michal Simek <michal.simek@xilinx.com>
Cc: Xiaobo Xie <X.Xie@freescale.com>
Cc: Anton Vorontsov <avorontsov@ru.mvista.com>
Cc: Soeren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20200701124702.908713-12-lee.jones@linaro.orgAcked-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>