MAINTAINERS: remove section LIBNVDIMM BLK: MMIO-APERTURE DRIVER

Commit f8669f1d6a86 ("nvdimm/blk: Delete the block-aperture window driver")
removes the file drivers/nvdimm/blk.c, but misses to adjust MAINTAINERS.

Hence, ./scripts/get_maintainer.pl --self-test=patterns complains about a
broken reference.

The section LIBNVDIMM BLK: MMIO-APERTURE DRIVER refers to the driver in
blk.c, and some more generic nvdimm code in region_devs.c.

As the driver is deleted, delete the section LIBNVDIMM BLK: MMIO-APERTURE
DRIVER in MAINTAINERS as well.

The remaining file region_devs.c is still covered by the section LIBNVDIMM:
NON-VOLATILE MEMORY DEVICE SUBSYSTEM, and all patches to region_devs.c will
still reach the same developers as before.

Signed-off-by: Lukas Bulwahn <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Dan Williams <[e-mail]>

MAINTAINERS

···
 F:	include/linux/ata.h
 F:	include/linux/libata.h
 
-LIBNVDIMM BLK: MMIO-APERTURE DRIVER
-M:	Dan Williams <[e-mail]>
-M:	Vishal Verma <[e-mail]>
-M:	Dave Jiang <[e-mail]>
-L:	[e-mail]
-S:	Supported
-Q:	https://patchwork.kernel.org/project/linux-nvdimm/list/
-P:	Documentation/nvdimm/maintainer-entry-profile.rst
-F:	drivers/nvdimm/blk.c
-F:	drivers/nvdimm/region_devs.c
-
 LIBNVDIMM BTT: BLOCK TRANSLATION TABLE
 M:	Vishal Verma <[e-mail]>
 M:	Dan Williams <[e-mail]>