Add a UEFI kernel configuration to include the VT kernel, and

replace the vt_vga driver with vt_efifb.

This is intended to help with snapshot builds only.

There is no intention to MFC this commit.

Sponsored by:	The FreeBSD Foundation

sys/amd64/conf/UEFI

@@ -0,0 +1,11 @@
+# VT -- kernel config using the vt(9) system console instead of legacy syscons
+#                                                                              
+# For more information see https://wiki.freebsd.org/Newcons
+#
+# $FreeBSD$
+
+include		VT
+ident 		UEFI
+
+nodevice 	vt_vga
+device		vt_efifb