MAINTAINERS: bitmap: add UAPI headers

The UAPI headers have been split out from the kernel-only headers.
They maintained as part of the bitmap library.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Signed-off-by: Yury Norov (NVIDIA) <yury.norov@gmail.com>

Author: t-8ch

MAINTAINERS

@@ -4181,6 +4181,7 @@ F:	include/linux/cpumask_types.h
 F:	include/linux/find.h
 F:	include/linux/nodemask.h
 F:	include/linux/nodemask_types.h
+F:	include/uapi/linux/bits.h
 F:	include/vdso/bits.h
 F:	lib/bitmap-str.c
 F:	lib/bitmap.c
@@ -4193,6 +4194,7 @@ F:	tools/include/linux/bitfield.h
 F:	tools/include/linux/bitmap.h
 F:	tools/include/linux/bits.h
 F:	tools/include/linux/find.h
+F:	tools/include/uapi/linux/bits.h
 F:	tools/include/vdso/bits.h
 F:	tools/lib/bitmap.c
 F:	tools/lib/find_bit.c