MIPS: BCM47XX: Detect more then 128 MiB of RAM (HIGHMEM)

So far BCM47XX can only detect amount of HIGHMEM. It still requires
adding (registering) and well-testing before enabling by default.

Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Acked-by: Hauke Mehrtens <hauke@hauke-m.de>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/7396/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/include/asm/pgtable-32.h b/arch/mips/include/asm/pgtable-32.h
index 2b11332..cd7d606 100644
--- a/arch/mips/include/asm/pgtable-32.h
+++ b/arch/mips/include/asm/pgtable-32.h
@@ -18,6 +18,8 @@
 
 #include <asm-generic/pgtable-nopmd.h>
 
+extern int temp_tlb_entry __cpuinitdata;
+
 /*
  * - add_temporary_entry() add a temporary TLB entry. We use TLB entries
  *	starting at the top and working down. This is for populating the