ARM: zynq: Fix default ps7_init_gpl.c/h for ZYBO

There is incorrect setting for USB which didn't work with origin
ps7_init_gpl.X files.
Use default setting for Digilent Zybo projects with HDMI in PL.

Signed-off-by: Michal Simek <monstr@monstr.eu>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>