drivers/intel/gma: Restructure IGD opregion init code

Restructuring opregion VBT related code to make it more generalize
for future revision of opregion spec.

Moved logic to locate VBT from different region (CBMEM, PCI option
ROM or VBIOS) into separate function.

Created a new function to check if extended VBT region is required.
This will be helpful in the subsequent changes to determine if
extended VBT region is needed and handle memory allocation
accordingly.

BUG=None
BRANCH=None
TEST=check the address of extended VBT region and address is coming
correctly.

Change-Id: I479d57cd326567192a3cd1969f8125ffe1934399
Signed-off-by: MAULIK V VAGHELA <maulik.v.vaghela@intel.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/55318
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-by: Nico Huber <nico.h@gmx.de>

0 files changed, 0 insertions, 0 deletions