MLK-12035 dts: imx7d-sdb-revb: add i.MX7d sdb revb support

MLK-12035 dts: imx7d-sdb-revb: add i.MX7d sdb revb support

Base on i.MX7d sdb revb board change list, below modules has changed:
 - enet2 and epdc enable pin
 - usb_otg2 pwr enable pin
 - ov5647_mipi pwr pin
 - tsc2046 touch pendown pin
 - uart5 tx/rx pins
 - sensor INT pin
 - pcie power is controlled by por_b, not gpio_spi pin6
 - hdmi audio change to SAI3 from SAI1

The patch add the changes for revb, and keep the original functions for
reva board. Remove redundancy sim and enet dts files to avoid excessive
dts file for reva and revb.

After the patch, there have below diff:
- default dts file: imx7d-sdb.dts for revb board, imx7d-sdb-reva.dts for reva board
- remove enet, sim extended dts files, so these modules are enabled in default dts
  file for reva and revb board.

The change of expanded dts due to pin confliction:
- Keep the original expanded name of dts file for revb board, add suffix "-reva" in dts
  file name for reva board.
- Like:
  hdmi/codec audio:
    hdmi audio and wm8960 codec are enabled in default dts file for revb board,
    no extended dts files to separate them.
    Keep original extended dts files for reva board:
	imx7d-sdb-reva-hdmi-audio.dts
	imx7d-sdb-reva-wm8960.dts
  epdc:
    imx7d-sdb-epdc.dts is for revb board, imx7d-sdb-reva-epdc.dts is for reva board.
  gpmi-weim:
    imx7d-sdb-gpmi-weim.dtsi for revb, imx7d-sdb-reva-gpmi-weim.dtsi for reva.
  m4:
    imx7d-sdb-m4.dts for revb, imx7d-sdb-reva-m4.dts for reva.
  qspi:
    imx7d-sdb-qspi.dts for revb, imx7d-sdb-reva-qspi.dts for reva.
  touchscreen:
    imx7d-sdb-touch.dts for revb, imx7d-sdb-reva-touch.dts for reva.

Cherry picked from commit: 2be1a236696d, and disable sai3 since there have many
Transmit underrun on kernel 4.1.

Signed-off-by: Fugang Duan <B38611@freescale.com>
Acked-by: Robby Cai <robby.cai@nxp.com>
Acked-by: Gao Pan <pandy.gao@nxp.com>
Acked-by: Peter Chen <peter.chen@freescale.com>
Acked-by: Chen Bough <Haibo.Chen@freescale.com>
Conflicts:
	arch/arm/boot/dts/Makefile
	arch/arm/boot/dts/imx7d-sdb-epdc.dts
	arch/arm/boot/dts/imx7d-sdb-gpmi-weim.dtsi
	arch/arm/boot/dts/imx7d-sdb-m4.dts
	arch/arm/boot/dts/imx7d-sdb-reva-epdc.dts
	arch/arm/boot/dts/imx7d-sdb-touch.dts
	arch/arm/boot/dts/imx7d-sdb.dts