vgabios: Add wrapper functions for accessing standard VGA registers.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
diff --git a/Makefile b/Makefile
index c97ed8f..31eb2f9 100644
--- a/Makefile
+++ b/Makefile
@@ -169,9 +169,10 @@
 ################ VGA build rules
 
 # VGA src files
-SRCVGA=src/output.c src/util.c src/pci.c vgasrc/vgabios.c vgasrc/vgafb.c \
-    vgasrc/vgatables.c vgasrc/vgafonts.c vgasrc/vbe.c \
-    vgasrc/stdvga.c vgasrc/clext.c vgasrc/bochsvga.c vgasrc/geodevga.c
+SRCVGA=src/output.c src/util.c src/pci.c \
+    vgasrc/vgabios.c vgasrc/vgafb.c vgasrc/vgafonts.c vgasrc/vbe.c \
+    vgasrc/vgatables.c vgasrc/stdvga.c vgasrc/stdvgaio.c \
+    vgasrc/clext.c vgasrc/bochsvga.c vgasrc/geodevga.c
 
 CFLAGS16VGA = $(CFLAGS16INC) -g -Isrc