powerpc/64s: Don't read H_BLOCK_REMOVE characteristics in radix mode

powerpc/64s: Don't read H_BLOCK_REMOVE characteristics in radix mode

There is no need to read the H_BLOCK_REMOVE characteristics when running in
Radix mode because this hcall is never called.

Furthermore since the commit 387e220a2e5e ("powerpc/64s: Move hash MMU
support code under CONFIG_PPC_64S_HASH_MMU") define
pseries_lpar_read_hblkrm_characteristics as un empty function if
CONFIG_PPC_64S_HASH_MMU is not set, the #ifdef block can be removed.

Signed-off-by: Laurent Dufour <ldufour@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220523164353.26441-1-ldufour@linux.ibm.com