POWERPC: Allow 32-bit hashed pgtable code to support 36-bit physical

This rearranges a bit of code, and adds support for
36-bit physical addressing for configs that use a
hashed page table.  The 36b physical support is not
enabled by default on any config - it must be
explicitly enabled via the config system.

This patch *only* expands the page table code to accomodate
large physical addresses on 32-bit systems and enables the
PHYS_64BIT config option for 86xx.  It does *not*
allow you to boot a board with more than about 3.5GB of
RAM - for that, SWIOTLB support is also required (and
coming soon).

Signed-off-by: Becky Bruce <becky.bruce@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
diff --git a/arch/powerpc/mm/tlb_32.c b/arch/powerpc/mm/tlb_32.c
index eb4b512..f9a47fe 100644
--- a/arch/powerpc/mm/tlb_32.c
+++ b/arch/powerpc/mm/tlb_32.c
@@ -45,6 +45,7 @@
 		flush_hash_pages(mm->context.id, addr, ptephys, 1);
 	}
 }
+EXPORT_SYMBOL(flush_hash_entry);
 
 /*
  * Called by ptep_set_access_flags, must flush on CPUs for which the