vgabios: Make VBE code depend on a config setting.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
diff --git a/vgasrc/Kconfig b/vgasrc/Kconfig
index f6dfa66..881e9ec 100644
--- a/vgasrc/Kconfig
+++ b/vgasrc/Kconfig
@@ -40,6 +40,13 @@
         bool
         default !NO_VGABIOS
 
+    config VGA_VBE
+        depends on BUILD_VGABIOS
+        bool "Video BIOS Extensions (VBE)"
+        default y
+        help
+            Support VBE.
+
     config VGA_PCI
         depends on BUILD_VGABIOS
         bool "PCI ROM Headers"
diff --git a/vgasrc/bochsvga.c b/vgasrc/bochsvga.c
index 0930b46..82629b9 100644
--- a/vgasrc/bochsvga.c
+++ b/vgasrc/bochsvga.c
@@ -121,7 +121,6 @@
         return -1;
     }
 
-    SET_VGA(VBE_enabled, 1);
     dispi_write(VBE_DISPI_INDEX_ID, VBE_DISPI_ID5);
 
     u32 lfb_addr;
diff --git a/vgasrc/clext.c b/vgasrc/clext.c
index eaef60a..f08294a 100644
--- a/vgasrc/clext.c
+++ b/vgasrc/clext.c
@@ -736,7 +736,6 @@
         return -1;
     dprintf(1, "cirrus init 2\n");
 
-    SET_VGA(VBE_enabled, 1);
     u32 lfb_addr = 0;
     if (CONFIG_VGA_PCI)
         lfb_addr = (pci_config_readl(GET_GLOBAL(VgaBDF), PCI_BASE_ADDRESS_0)
diff --git a/vgasrc/vbe.c b/vgasrc/vbe.c
index 14efece..d7dd8b4 100644
--- a/vgasrc/vbe.c
+++ b/vgasrc/vbe.c
@@ -13,7 +13,6 @@
 #include "biosvar.h" // get_global_set
 #include "vgahw.h" // vgahw_set_mode
 
-int VBE_enabled VAR16;
 u32 VBE_total_memory VAR16 = 256 * 1024;
 u32 VBE_capabilities VAR16;
 u32 VBE_framebuffer VAR16;
@@ -257,7 +256,7 @@
 void
 handle_104f(struct bregs *regs)
 {
-    if (!GET_GLOBAL(VBE_enabled)) {
+    if (!CONFIG_VGA_VBE) {
         vbe_104fXX(regs);
         return;
     }
diff --git a/vgasrc/vgabios.h b/vgasrc/vgabios.h
index a10198d..403e7ce 100644
--- a/vgasrc/vgabios.h
+++ b/vgasrc/vgabios.h
@@ -93,7 +93,6 @@
 u8 vgafb_read_pixel(u16 x, u16 y);
 
 // vbe.c
-int VBE_enabled;
 u32 VBE_total_memory;
 u32 VBE_capabilities;
 u32 VBE_framebuffer;