x86 setup: remove remnants of CONFIG_VIDEO_SELECT (read: vga=)

Impact: cleanup

Video mode selection became always possible in 2.6.23-rc1 after i386 setup
code rewrite in C.

Regardless, VIDEO_SELECT is stupid config option because it affects only
kernel setup code, not code which always stays in memory.

vga= always possible now which is good.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>