board/freescale/common:Add support of QTAG register

board/freescale/common:Add support of QTAG register

QIXIS FPGA's QIXIS Tag Access register (QTAG) defines TAG, VER, DATE, IMAGE
fields. These fields have FPGA build version, image name and build date
information.

Add support to parse these fields to have complete FPGA image information.

Signed-off-by: York Sun <yorksun@freescale.com>
Signed-off-by: Prabhakar Kushwaha <prabhakar@freescale.com>
Signed-off-by: Poonam Aggrwal <poonam.aggrwal@freescale.com>
Signed-off-by: Andy Fleming <afleming@freescale.com>