MAINTAINERS: Add some header files to the PC chipset section

These header files obviously belong to the PC chipset (since
their names match the other .c files in this section).
Signed-off-by: NThomas Huth <thuth@redhat.com>
Message-Id: <1473111075-25311-1-git-send-email-thuth@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

MAINTAINERS

@@ -715,6 +715,10 @@ F: hw/misc/pc-testdev.c
 F: hw/timer/hpet*
 F: hw/timer/i8254*
 F: hw/timer/mc146818rtc*
+F: include/hw/i2c/pm_smbus.h
+F: include/hw/timer/hpet.h
+F: include/hw/timer/i8254*
+F: include/hw/timer/mc146818rtc*
 
 Machine core
 M: Eduardo Habkost <ehabkost@redhat.com>