[PATCH] FRV: Update the FRV arch MAINTAINER record to get a hit on "grep -i frv"

Update the FRV arch MAINTAINER record to get a hit on "grep -i frv".  Whilst
FR-V is technically correct, it's normally thought of as FRV.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>