Haswell and model_2065 implement a static set_msr_bit helper which
should be publicly available instead. Move it to cpu/x86.
Change-Id: I68b314c917f15fc6e5351de1c539d5a3ae646df8
Signed-off-by: Michael Niewöhner <foss@mniewoehner.de>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/36338
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-by: Nico Huber <nico.h@gmx.de>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>