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 387e220a ("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

arch/powerpc/platforms/pseries/setup.c

@@ -803,9 +803,8 @@ static void __init pSeries_setup_arch(void)
 	fwnmi_init();
 
 	pseries_setup_security_mitigations();
-#ifdef CONFIG_PPC_64S_HASH_MMU
-	pseries_lpar_read_hblkrm_characteristics();
-#endif
+	if (!radix_enabled())
+		pseries_lpar_read_hblkrm_characteristics();
 
 	/* By default, only probe PCI (can be overridden by rtas_pci) */
 	pci_add_flags(PCI_PROBE_ONLY);