sunxi: Convert CONFIG_MACPWR to Kconfig

Convert the CONFIG_MACPWR to Kconfig and update all the sunxi defconfigs
that used it in SYS_EXTRA_OPTIONS.

Signed-off-by: Mylène Josserand <mylene.josserand@free-electrons.com>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
diff --git a/configs/mixtile_loftq_defconfig b/configs/mixtile_loftq_defconfig
index 591f481..6264b3a 100644
--- a/configs/mixtile_loftq_defconfig
+++ b/configs/mixtile_loftq_defconfig
@@ -2,12 +2,12 @@
 CONFIG_ARCH_SUNXI=y
 CONFIG_MACH_SUN6I=y
 CONFIG_DRAM_ZQ=251
+CONFIG_MACPWR="PA21"
 CONFIG_MMC_SUNXI_SLOT_EXTRA=2
 CONFIG_USB1_VBUS_PIN="PH24"
 CONFIG_USB2_VBUS_PIN=""
 CONFIG_DEFAULT_DEVICE_TREE="sun6i-a31-mixtile-loftq"
 # CONFIG_SYS_MALLOC_CLEAR_ON_INIT is not set
-CONFIG_SYS_EXTRA_OPTIONS="MACPWR=SUNXI_GPA(21)"
 CONFIG_SPL=y
 # CONFIG_CMD_IMLS is not set
 # CONFIG_CMD_FLASH is not set