MAINTAINERS: OMAP POWERDOMAIN, update patterns

Commit 49815399 ("ARM: OMAP2+: powerdomain/PRM: move the low-level
powerdomain") renamed the files, update the patterns.

Identical to a patch earlier sent by Cesar Eduardo Barros.

Signed-off-by: Joe Perches <joe@perches.com>
Cc: Paul Walmsley <paul@pwsan.com>
Cc: Rajendra Nayak <rnayak@ti.com>
Cc: Santosh Shilimkar <santosh.shilimkar@ti.com>
Cc: Cesar Eduardo Barros <cesarb@cesarb.eti.br>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>