fsp_baytrail: remove version from default vbios path

Intel requested that we remove the version number from the default
vbios path.

Change-Id: I2590fed0db157e3e430212336fc55eb099d28a72
Signed-off-by: Martin Roth <martin.roth@se-eng.com>
Reviewed-on: http://review.coreboot.org/5984
Tested-by: build bot (Jenkins)
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Marc Jones <marc.jones@se-eng.com>