Change in coreboot[master]: drivers/intel/gma: Move extended VBT just below opregion

[Maulik V Vaghela (Code Review)]

Attention is currently required from: Nico Huber, Furquan Shaikh, Angel Pons, Tim Wawrzynczak, Patrick Rudolph.
Maulik V Vaghela has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/55341 )

Change subject: drivers/intel/gma: Move extended VBT just below opregion
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Patch Set 3:

(2 comments)

File src/drivers/intel/gma/opregion.c:

https://review.coreboot.org/c/coreboot/+/55341/comment/3991b247_4757014a 
PS2, Line 271: static void opregion_add_ext_vbt(igd_opregion_t *opregion, uint8_t *ext_vbt, optionrom_vbt_t *vbt)
> Does this need to be a separate function?

Ack. Yes Angel, Actually we're planning to scale it and use it for OPREGION 2.1 as well.
In case of 2.1 version, we need to pass relative address of VBT in RVDA as opposed to actual address. So to handle this case, I am making it as a separate function so that we won't clutter base function with conditions.

https://review.coreboot.org/c/coreboot/+/55341/comment/14436d78_b74c3a04 
PS2, Line 288: uint32_t
> `size_t` would be more accurate. […]

Done