powerpc/nohash: Remove pte_same()

arch/powerpc/include/asm/nohash/{32/64}/pgtable.h has

	#define __HAVE_ARCH_PTE_SAME
	#define pte_same(A,B)      ((pte_val(A) ^ pte_val(B)) == 0)

include/linux/pgtable.h has

	#ifndef __HAVE_ARCH_PTE_SAME
	static inline int pte_same(pte_t pte_a, pte_t pte_b)
	{
		return pte_val(pte_a) == pte_val(pte_b);
	}
	#endif

Remove the powerpc version which is similar to the generic one.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/83c97bd58a3596ef1b0ff28b1e41fd492d005520.1643616989.git.christophe.leroy@csgroup.eu

arch/powerpc/include/asm/nohash/32/pgtable.h

@@ -338,9 +338,6 @@ static inline int pte_young(pte_t pte)
 	return pte_val(pte) & _PAGE_ACCESSED;
 }
 
-#define __HAVE_ARCH_PTE_SAME
-#define pte_same(A,B)	((pte_val(A) ^ pte_val(B)) == 0)
-
 /*
  * Note that on Book E processors, the pmd contains the kernel virtual
  * (lowmem) address of the pte page.  The physical address is less useful

arch/powerpc/include/asm/nohash/64/pgtable.h

@@ -281,9 +281,6 @@ static inline void __ptep_set_access_flags(struct vm_area_struct *vma,
 	flush_tlb_page(vma, address);
 }
 
-#define __HAVE_ARCH_PTE_SAME
-#define pte_same(A,B)	((pte_val(A) ^ pte_val(B)) == 0)
-
 #define pte_ERROR(e) \
 	pr_err("%s:%d: bad pte %08lx.\n", __FILE__, __LINE__, pte_val(e))
 #define pmd_ERROR(e) \