mb/asus/h61-series: Always select `INTEL_INT15`
The mainboard.c guard was only added to preserve reproducibility when
unifying the boards. The `install_intel_vga_int15_handler` function does
nothing when `VGA_ROM_RUN` is not selected. Remove the guard and always
select `INTEL_INT15` for simplicity.
Change-Id: If51a0ab1c57b0856018a62cf669e5d1b53e5333c
Signed-off-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/54379
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Patrick Georgi <pgeorgi@google.com>