MAINTAINERS: update for TI OMAP hsmmc driver

Update maintainers entry for TI OMAP HS MMC support.

Signed-off-by: Madhusudhan Chikkature <madhu.cr@ti.com>
Acked-by: Kevin Hilman <khilman@deeprootsystems.com>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>