MAINTAINERS: update X86 machine entry

Add a bunch of files missing, and add self as maintainer.  Since I'm
hacking on these anyway, it will be helpful if people Cc me on patches.
Anthony gets to review everything anyway ...

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

MAINTAINERS

@@ -500,9 +500,23 @@ X86 Machines
 ------------
 PC
 M: Anthony Liguori <aliguori@amazon.com>
+M: Michael S. Tsirkin <mst@redhat.com>
 S: Supported
-F: hw/i386/pc.[ch]
-F: hw/i386/pc_piix.c
+F: include/hw/i386/
+F: hw/i386/
+F: hw/pci-host/piix.c
+F: hw/pci-host/q35.c
+F: hw/pci-host/pam.c
+F: include/hw/pci-host/q35.h
+F: include/hw/pci-host/pam.h
+F: hw/isa/piix4.c
+F: hw/isa/lpc_ich9.c
+F: hw/i2c/smbus_ich9.c
+F: hw/acpi/piix4.c
+F: hw/acpi/ich9.c
+F: include/hw/acpi/ich9.h
+F: include/hw/acpi/piix.h
+
 
 Xtensa Machines
 ---------------