MIPS: Remove redundant asm/pgtable-bits.h inclusions

MIPS: Remove redundant asm/pgtable-bits.h inclusions

asm/pgtable-bits.h is included in 2 assembly files and thus has to
ifdef around C code, however nothing defined by the header is used
in either of the assembly files that include it.

Remove the redundant inclusions such that asm/pgtable-bits.h doesn't
need to #ifdef around C code, for cleanliness and in preparation for
later patches which will add more C.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Reviewed-by: James Hogan <james.hogan@imgtec.com>
Cc: Maciej W. Rozycki <macro@linux-mips.org>
Cc: Jonas Gorski <jogo@openwrt.org>
Cc: Alex Smith <alex.smith@imgtec.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13114/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>