media: davinci_vpfe: don't use kernel-doc markup for simple comments

Fix those two warnings:
   drivers/staging/media/davinci_vpfe/vpfe_mc_capture.c:90: warning: Function parameter or member 'interface' not described in 'MODULE_PARM_DESC'
   drivers/staging/media/davinci_vpfe/vpfe_mc_capture.c:90: warning: Function parameter or member '(default' not described in 'MODULE_PARM_DESC'

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>