pwm: Update MAINTAINER entry

There is little sense in having gpio-mvebu and pwm-backlight explicitly
listed in the PWM entry. Drop these and add the keywords that actually
identify a driver as PWM related.

Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
Link: https://patch.msgid.link/20260115165055.1739004-2-ukleinek@kernel.org
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>

Author: Uwe Kleine-König

MAINTAINERS

@@ -21070,16 +21070,14 @@ L:	linux-pwm@vger.kernel.org
 S:	Maintained
 Q:	https://patchwork.ozlabs.org/project/linux-pwm/list/
 T:	git https://git.kernel.org/pub/scm/linux/kernel/git/ukleinek/linux.git
-F:	Documentation/devicetree/bindings/gpio/gpio-mvebu.yaml
 F:	Documentation/devicetree/bindings/pwm/
 F:	Documentation/driver-api/pwm.rst
-F:	drivers/gpio/gpio-mvebu.c
 F:	drivers/pwm/
-F:	drivers/video/backlight/pwm_bl.c
 F:	include/dt-bindings/pwm/
 F:	include/linux/pwm.h
-F:	include/linux/pwm_backlight.h
 K:	pwm_(config|apply_might_sleep|apply_atomic|ops)
+K:	(devm_)?pwmchip_(add|alloc|remove)
+K:	pwm_(round|get|set)_waveform
 
 PWM SUBSYSTEM BINDINGS [RUST]
 M:	Michal Wilczynski <m.wilczynski@samsung.com>