drivers/qemu: Drop redundant vga_io addition to ramstage

While introducing driver support for QEMU Cirrus display device, commit
7905f9254ebc ("qemu: cirrus native video init") also explicitly adds
VGA I/O functions into ramstage class when Bochs display driver support
is enabled.

Later, commit db7d04d1b753 ("qemu: Support textmode gfx init.") makes
the related config option select CONFIG_VGA, which also adds the same
file into ramstage class (among other things) in another Makefile.

Doing this twice is unnecessary. Remove the addition based on the Bochs
display driver's config option. Adding it based on CONFIG_VGA is
clearer, and future patches will try to support a Bochs display without
legacy VGA support on non-x86 architectures.

Change-Id: Ib31344e242689682d74d8a83c97b6e8027641926
Signed-off-by: Alper Nebi Yasak <alpernebiyasak@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/80374
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Nico Huber <nico.h@gmx.de>
diff --git a/src/drivers/emulation/qemu/Makefile.mk b/src/drivers/emulation/qemu/Makefile.mk
index 6f5ff3a..c9d94bd 100644
--- a/src/drivers/emulation/qemu/Makefile.mk
+++ b/src/drivers/emulation/qemu/Makefile.mk
@@ -7,4 +7,3 @@
 
 ramstage-$(CONFIG_DRIVERS_EMULATION_QEMU_BOCHS) += bochs.c
 ramstage-$(CONFIG_DRIVERS_EMULATION_QEMU_BOCHS) += cirrus.c
-ramstage-$(CONFIG_DRIVERS_EMULATION_QEMU_BOCHS) += ../../pc80/vga/vga_io.c