MAINTAINERS: add coverage for drivers/block

To help folks like me that use scripts/get_maintainer.pl.

Signed-off-by: Ross Zwisler <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>

Author: Ross Zwisler

MAINTAINERS

@@ -2683,6 +2683,7 @@ L:	[email protected]
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux-block.git
 S:	Maintained
 F:	block/
+F:	drivers/block/
 F:	kernel/trace/blktrace.c
 F:	lib/sbitmap.c