arc: drop definitions of pgd_index() and pgd_offset{, _k}() entirely

They were in <asm/pgtables.h> and have been removed from there in
974b9b2c ("mm: consolidate pte_index() and pte_offset_*() definitions")
in favor of the generic version. But that missed that the same definitons
also existed in <asm/pgtable-levels.h>, where they were (inadvertently?)
introduced in fe6cb7b0 ("ARC: mm: disintegrate pgtable.h into levels
and flags").

Fixes: 974b9b2c ("mm: consolidate pte_index() and pte_offset_*() definitions")
Fixes: fe6cb7b0 ("ARC: mm: disintegrate pgtable.h into levels and flags")
Signed-off-by: Rolf Eike Beer <eb@emlix.com>
Signed-off-by: Vineet Gupta <vgupta@kernel.org>

arch/arc/include/asm/pgtable-levels.h

@@ -98,9 +98,6 @@
 /*
  * 1st level paging: pgd
  */
-#define pgd_index(addr)		((addr) >> PGDIR_SHIFT)
-#define pgd_offset(mm, addr)	(((mm)->pgd) + pgd_index(addr))
-#define pgd_offset_k(addr)	pgd_offset(&init_mm, addr)
 #define pgd_ERROR(e) \
 	pr_crit("%s:%d: bad pgd %08lx.\n", __FILE__, __LINE__, pgd_val(e))