build: add pc-bios to config-host.mak deps

... so configure re-runs on pc-bios updates such as new pxe roms.
Needed because configure symlinks the prebuilt roms from src
into build tree.
Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>

Makefile

@@ -30,7 +30,7 @@ CONFIG_ALL=y
 -include config-all-devices.mak
 -include config-all-disas.mak
 
-config-host.mak: $(SRC_PATH)/configure
+config-host.mak: $(SRC_PATH)/configure $(SRC_PATH)/pc-bios
 	@echo $@ is out-of-date, running configure
 	@# TODO: The next lines include code which supports a smooth
 	@# transition from old configurations without config.status.