KVM: PPC: Book3S HV: Fix conversion to gfn-based MMU notifier callbacks

Commit b1c5356e ("KVM: PPC: Convert to the gfn-based MMU notifier
callbacks") causes unmap_gfn_range and age_gfn callbacks to only work
on the first gfn in the range. It also makes the aging callbacks call
into both radix and hash aging functions for radix guests. Fix this.

Add warnings for the single-gfn calls that have been converted to range
callbacks, in case they ever receieve ranges greater than 1.

Fixes: b1c5356e ("KVM: PPC: Convert to the gfn-based MMU notifier callbacks")
Reported-by: Bharata B Rao <bharata@linux.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Tested-by: Bharata B Rao <bharata@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210505121509.1470207-1-npiggin@gmail.com