MIPS: Malta: Setup PM I/O region on boot

This patch ensures that the kernel sets a sane base address for the
PIIX4 PM I/O register region during boot. Without this the kernel may
not successfully claim the region as a resource if the bootloader didn't
configure the region. With this patch the kernel will always succeed
with:

  pci 0000:00:0a.3: quirk: [io  0x1000-0x103f] claimed by PIIX4 ACPI

The lack of the resource claiming is easily reproducible without this
patch using current versions of QEMU.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Tested-by: James Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/6641/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/include/asm/mips-boards/piix4.h

@@ -50,4 +50,9 @@
 #define PIIX4_FUNC1_IDETIM_SECONDARY_HI		0x43
 #define   PIIX4_FUNC1_IDETIM_SECONDARY_HI_IDE_DECODE_EN	(1 << 7)
 
+/* Power Management Configuration Space */
+#define PIIX4_FUNC3_PMBA			0x40
+#define PIIX4_FUNC3_PMREGMISC			0x80
+#define   PIIX4_FUNC3_PMREGMISC_EN			(1 << 0)
+
 #endif /* __ASM_MIPS_BOARDS_PIIX4_H */