x86/platform/uv: Remove vestigial mention of UV1 platform from bios header

Remove UV1 reference as UV1 is not longer supported by HPE.

Signed-off-by: Steve Wahl <steve.wahl@hpe.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20200713212955.435951508@hpe.com