ARM: pxa: change gpio to platform device

Remove most gpio macros and change gpio driver to platform driver.

Signed-off-by: Haojian Zhuang <haojian.zhuang@marvell.com>
diff --git a/arch/arm/mach-mmp/brownstone.c b/arch/arm/mach-mmp/brownstone.c
index 983cfb1..eb07565 100644
--- a/arch/arm/mach-mmp/brownstone.c
+++ b/arch/arm/mach-mmp/brownstone.c
@@ -202,6 +202,7 @@
 	/* on-chip devices */
 	mmp2_add_uart(1);
 	mmp2_add_uart(3);
+	platform_device_register(&mmp2_device_gpio);
 	mmp2_add_twsi(1, NULL, ARRAY_AND_SIZE(brownstone_twsi1_info));
 	mmp2_add_sdhost(0, &mmp2_sdh_platdata_mmc0); /* SD/MMC */
 	mmp2_add_sdhost(2, &mmp2_sdh_platdata_mmc2); /* eMMC */