x86/platform/uv: Remove SCIR MMR references for UV systems

UV class systems no longer use System Controller for monitoring of CPU
activity provided by this driver. Other methods have been developed for
BIOS and the management controller (BMC). Remove that supporting code.

Signed-off-by: Mike Travis <mike.travis@hpe.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Dimitri Sivanich <dimitri.sivanich@hpe.com>
Link: https://lkml.kernel.org/r/20201005203929.148656-3-mike.travis@hpe.com