vgabios: Add support for vbe get/set line length function.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
diff --git a/vgasrc/vgahw.h b/vgasrc/vgahw.h
index ca8798c..494309b 100644
--- a/vgasrc/vgahw.h
+++ b/vgasrc/vgahw.h
@@ -61,4 +61,20 @@
     return stdvga_set_window(vmode_g, window, val);
 }
 
+static inline int vgahw_get_linelength(struct vgamode_s *vmode_g) {
+    if (CONFIG_VGA_CIRRUS)
+        return clext_get_linelength(vmode_g);
+    if (CONFIG_VGA_BOCHS)
+        return bochsvga_get_linelength(vmode_g);
+    return stdvga_get_linelength(vmode_g);
+}
+
+static inline int vgahw_set_linelength(struct vgamode_s *vmode_g, int val) {
+    if (CONFIG_VGA_CIRRUS)
+        return clext_set_linelength(vmode_g, val);
+    if (CONFIG_VGA_BOCHS)
+        return bochsvga_set_linelength(vmode_g, val);
+    return stdvga_set_linelength(vmode_g, val);
+}
+
 #endif // vgahw.h