apalis_imx6: clean-up and migrate gpios to using driver model

Migrate GPIOs to using driver model, properly request backlight,
Ethernet PHY reset, MMC/SD card detect and USB power GPIOs and also
enable SION bit in pin muxing for Apalis, backlight, eMMC reset,
Ethernet PHY reset and USB power enable GPIOs.

While at it also update copyright year, clean-up/re-order includes,
add some comments clarifying ifdef scope and do some White-space
clean-up.

Signed-off-by: Marcel Ziswiler <marcel.ziswiler@toradex.com>
diff --git a/configs/apalis_imx6_defconfig b/configs/apalis_imx6_defconfig
index 985d855..0f6119b 100644
--- a/configs/apalis_imx6_defconfig
+++ b/configs/apalis_imx6_defconfig
@@ -51,6 +51,7 @@
 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG=y
 CONFIG_DWC_AHSATA=y
 CONFIG_DFU_MMC=y
+CONFIG_DM_GPIO=y
 CONFIG_FSL_ESDHC=y
 CONFIG_PHYLIB=y
 CONFIG_PHY_MICREL=y