x86/platform/uv: Remove the unused _uv_cpu_blade_processor_id() macro

No users anywhere in the kernel tree.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Not-acked-by: Dimitri Sivanich <sivanich@hpe.com>
Cc: Russ Anderson <rja@hpe.com>
Link: https://lkml.kernel.org/r/20200504171527.2845224-12-hch@lst.de