device/oprom/realmode: Add vbe return status support as per VBE spec 3.0

device/oprom/realmode: Add vbe return status support as per VBE spec 3.0

Existing coreboot oprom implementation relies on user selected
vesa mode through CONFIG_FRAMEBUFFER_VESA_MODE Kconfig option
and expects that all oprom might support user selected vesa mode.

Take an example:
Enabling AMD external radeon PCIE graphics card on ICLRVP with
default vesa mode 0x118. Unable to get valid X and Y resolution
after executing vbe_get_mode_info() with 0x4118, return data
buffer shows 0x0 resolution. It causes further hang while trying
to draw bmpblk image at depthcharge.

This patch checks for output register AH in all vbe function
(0x3 and 0x4f00/1/2) and die() if returns error.

Change-Id: Iacd2ce468e038a14424f029df3a0adec3e5fa15c
Signed-off-by: Subrata Banik <subrata.banik@intel.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/33737
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Patrick Georgi <pgeorgi@google.com>