ARM: sunxi: Add a defconfig for the Allwinner SoCs

So far, the Allwinner SoCs were only supported using the
multi_v7_defconfig. Add a defconfig of our own to have one a bit more
tailor-made.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

arch/arm/configs/sunxi_defconfig

+CONFIG_NO_HZ=y
+CONFIG_HIGH_RES_TIMERS=y
+CONFIG_BLK_DEV_INITRD=y
+CONFIG_ARCH_SUNXI=y
+CONFIG_SMP=y
+CONFIG_AEABI=y
+CONFIG_HIGHMEM=y
+CONFIG_HIGHPTE=y
+CONFIG_VFP=y
+CONFIG_NEON=y
+CONFIG_NET=y
+CONFIG_PACKET=y
+CONFIG_UNIX=y
+CONFIG_INET=y
+# CONFIG_INET_XFRM_MODE_TRANSPORT is not set
+# CONFIG_INET_XFRM_MODE_TUNNEL is not set
+# CONFIG_INET_XFRM_MODE_BEET is not set
+# CONFIG_INET_LRO is not set
+# CONFIG_INET_DIAG is not set
+# CONFIG_IPV6 is not set
+# CONFIG_WIRELESS is not set
+CONFIG_DEVTMPFS=y
+CONFIG_DEVTMPFS_MOUNT=y
+CONFIG_NETDEVICES=y
+CONFIG_SUN4I_EMAC=y
+# CONFIG_NET_CADENCE is not set
+# CONFIG_NET_VENDOR_BROADCOM is not set
+# CONFIG_NET_VENDOR_CIRRUS is not set
+# CONFIG_NET_VENDOR_FARADAY is not set
+# CONFIG_NET_VENDOR_INTEL is not set
+# CONFIG_NET_VENDOR_MARVELL is not set
+# CONFIG_NET_VENDOR_MICREL is not set
+# CONFIG_NET_VENDOR_NATSEMI is not set
+# CONFIG_NET_VENDOR_SEEQ is not set
+# CONFIG_NET_VENDOR_SMSC is not set
+# CONFIG_NET_VENDOR_STMICRO is not set
+# CONFIG_NET_VENDOR_WIZNET is not set
+# CONFIG_WLAN is not set
+CONFIG_SERIAL_8250=y
+CONFIG_SERIAL_8250_CONSOLE=y
+CONFIG_SERIAL_8250_NR_UARTS=8
+CONFIG_SERIAL_8250_RUNTIME_UARTS=8
+CONFIG_SERIAL_8250_DW=y
+CONFIG_I2C=y
+# CONFIG_I2C_COMPAT is not set
+CONFIG_I2C_CHARDEV=y
+CONFIG_I2C_MV64XXX=y
+CONFIG_GPIO_SYSFS=y
+# CONFIG_HWMON is not set
+CONFIG_WATCHDOG=y
+CONFIG_SUNXI_WATCHDOG=y
+# CONFIG_USB_SUPPORT is not set
+CONFIG_NEW_LEDS=y
+CONFIG_LEDS_CLASS=y
+CONFIG_LEDS_GPIO=y
+CONFIG_LEDS_TRIGGERS=y
+CONFIG_LEDS_TRIGGER_HEARTBEAT=y
+CONFIG_LEDS_TRIGGER_DEFAULT_ON=y
+CONFIG_COMMON_CLK_DEBUG=y
+# CONFIG_IOMMU_SUPPORT is not set
+CONFIG_NLS=y