mmc-utils: manpage: fix arguments for TH macro

According to man-pages(7) the TH macro takes the following parameters:

	.TH title section date source manual

with some recommendations for the individual parameters. Adapt the usage
of TH accordingly. The motivating change is to drop "man" in the title
in favor of "MMC".
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Chris Ball <chris@printf.net>

man/mmc.1

-.TH man 1 "16 November 2015" "0.1" "mmc-utils man page"
+.TH MMC 1 "2015-11-16" "0.1" "mmc-utils"
 .SH
 NAME
 mmc-utils \- Configure MMC storage devices from userspace.