board/t1040qds: Relax IFC FPGA timings

Current IFC-FPGA TCH(Chip Select hold time with respect to WE deassertion)
is 0 i.e. 0 ns hold time on writes. This may not work on higher clock
freqencies.

So, Increase TCH as 0x8 i.e. 8 ip_clk.

Signed-off-by: Prabhakar Kushwaha <prabhakar@freescale.com>