ARM: pgtable: collect up identity mapping functions

We have two places where we create identity mappings - one when we bring
secondary CPUs online, and one where we setup some mappings for soft-
reboot.  Combine these two into a single implementation.  Also collect
the identity mapping deletion function.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/include/asm/pgtable.h b/arch/arm/include/asm/pgtable.h
index e582214..1e31af2 100644
--- a/arch/arm/include/asm/pgtable.h
+++ b/arch/arm/include/asm/pgtable.h
@@ -474,6 +474,9 @@
 
 #define pgtable_cache_init() do { } while (0)
 
+void identity_mapping_add(pgd_t *, unsigned long, unsigned long);
+void identity_mapping_del(pgd_t *, unsigned long, unsigned long);
+
 #endif /* !__ASSEMBLY__ */
 
 #endif /* CONFIG_MMU */