ACPI / video: Ignore BIOS initial backlight value for HP 250 G1

On HP 250 G1 laptops, BIOS reports minimum backlight on boot and
causes backlight to dim completely. This ignores the initial backlight
values and set to max brightness.

References: https://bugzilla.kernel.org/show_bug.cgi?id=63111


Signed-off-by: Kirill Tkhai <tkhai@yandex.ru>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>