MAINTAINERS: Update SCMI entry with HWMON driver

scmi-hwmon.c is tightly coupled with the SCMI subsystem, fold it under
the SCMI subsystem MAINTAINERS umbrella.

Signed-off-by: Florian Fainelli <florian.fainelli@broadcom.com>
Link: https://lore.kernel.org/r/20240222193027.920006-1-florian.fainelli@broadcom.com
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

Author: ffainelli

MAINTAINERS

@@ -21321,6 +21321,7 @@ F:	drivers/clk/clk-sc[mp]i.c
 F:	drivers/cpufreq/sc[mp]i-cpufreq.c
 F:	drivers/firmware/arm_scmi/
 F:	drivers/firmware/arm_scpi.c
+F:	drivers/hwmon/scmi-hwmon.c
 F:	drivers/pmdomain/arm/
 F:	drivers/powercap/arm_scmi_powercap.c
 F:	drivers/regulator/scmi-regulator.c