powerpc/32: Allow fragmented physical memory

Since commit 9e849f231c ("powerpc/mm/32s: use generic mmu_mapin_ram()
for all blocks.") it is possible to map all blocks as RAM on any PPC32.

Remove related restrictions.

And remove call to wii_memory_fixups() which doesn't do anything else
than checks since commit 160985f302 ("powerpc/wii: remove
wii_mmu_mapin_mem2()")

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/fc9a5b8ef49f6eb86e970d4c7ccfba9b407fd4eb.1661938317.git.christophe.leroy@csgroup.eu

arch/powerpc/mm/init_32.c

@@ -82,15 +82,6 @@ void __init MMU_init(void)
 	if (ppc_md.progress)
 		ppc_md.progress("MMU:enter", 0x111);
 
-	if (memblock.memory.cnt > 1) {
-#ifndef CONFIG_WII
-		memblock_enforce_memory_limit(memblock.memory.regions[0].size);
-		pr_warn("Only using first contiguous memory region\n");
-#else
-		wii_memory_fixups();
-#endif
-	}
-
 	total_lowmem = total_memory = memblock_end_of_DRAM() - memstart_addr;
 	lowmem_end_addr = memstart_addr + total_lowmem;