Add TQ Systems TQMa6 board support

Add TQ Systems TQMa6 board support

This patch adds the changes to boards.cfg and the board directory
under board/tqc.

TQMa6 is a family of modules based on Freescale i.MX6. It consists of
TQMa6Q (i.MX6 Quad), TQMa6D (i.MX6 Dual) featuring eMMC, and 1 GiB DDR3
TQMa6S (i.MX6 Solo)  featuring eMMC and 512 MiB DDR3

The modules need a baseboard. Initially the MBa6x starterkit mainboard is
supported. To easy support for other mainboards the functionality is splitted
in one file for the module (tqma6.c) and one file for the baseboard (tqma6_
mba6).

The modules can be boot from eMMC (on USDHC3) and SPI flash.

The following features are supported:
- MMC: eMMC on module (on USDHC3) and SD-card (on MBa6x mainboard)
- Ethernet: RGMII using micrel KSZ9031 phy on MBa6x mainboard for TQMa6<x> module.
  The phy needs special configurations for the pad skew registers to adjust for
  the signal routing.
  Also support for standard ethernet commands and uppdate via tftp.
- SPI: ECSPI1 with bootable serial flash on module and two additional
  chip selects on MBa6x
- I2C: This patch adds support for the I2C busses on the TQMa6<x> modules (I2C3)
  and MBa6x baseboards (I2C1). The LM75 temperature sensors on TQMa6<x> and MBa6x
  are also configured.
- USB: high speed host 1 on MBa6x and support for USB storage
- PMIC: support for pfuze 100 on TQMa6<x>

Signed-off-by: Markus Niebel <Markus.Niebel@tq-group.com>