sparc32: remove custom definition of mk_pte()

sparc32: remove custom definition of mk_pte()

Instead of defining pfn_pte() in terms of mk_pte(), make pfn_pte() the
base implementation.  That lets us use the generic definition of mk_pte().

Link: https://lkml.kernel.org/r/20250402181709.2386022-4-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Zi Yan <ziy@nvidia.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Andreas Larsson <andreas@gaisler.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Richard Weinberger <richard@nod.at>
Cc: <x86@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>