KVM: PPC: Book3S HV: Remove KVMPPC_NR_LPIDS

KVMPPC_NR_LPIDS no longer represents any size restriction on the
LPID space and can be removed. A CPU with more than 12 LPID bits
implemented will now be able to create more than 4095 guests.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220123120043.3586018-7-npiggin@gmail.com