arm64/mm: Drop SWAPPER_INIT_MAP_SIZE

The commit cdef5f6e ("arm64: mm: allocate pagetables anywhere") had
dropped the last reference to SWAPPER_INIT_MAP_SIZE. Hence just clean up.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Link: https://lore.kernel.org/r/1623665411-20055-1-git-send-email-anshuman.khandual@arm.comSigned-off-by: Will Deacon <will@kernel.org>

arch/arm64/include/asm/kernel-pgtable.h

@@ -100,9 +100,6 @@
 #define SWAPPER_TABLE_SHIFT	PMD_SHIFT
 #endif
 
-/* The size of the initial kernel direct mapping */
-#define SWAPPER_INIT_MAP_SIZE	(_AC(1, UL) << SWAPPER_TABLE_SHIFT)
-
 /*
  * Initial memory map attributes.
  */