kernel/vga: Remove VGA_NO_BIOS and VGA_ALT_SEQACCESS options.

kernel/vga: Remove VGA_NO_BIOS and VGA_ALT_SEQACCESS options.

VGA_NO_BIOS and VGA_NO_MODE_CHANGE were overlapping 90% or more in
functionality, so remove the former (which is internal anyway) and
use VGA_NO_MODE_CHANGE there too.

Also remove VGA_ALT_SEQACCESS which provided some alternate way to
access the VGA sequencer. I've not heard of anyone needing this
option ever, so assume that it is no longer needed. It can be brought
back if it turns out to be important to anyone.

In-discussion-with: ivadasz