[ARM] Add section support to ioremap

Allow section mappings to be setup using ioremap() and torn down
with iounmap().  This requires additional support in the MM
context switch to ensure that mappings are properly synchronised
when mapped in.

Based an original implementation by Deepak Saxena, reworked and
ARMv6 support added by rmk.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/include/asm-arm/mmu.h b/include/asm-arm/mmu.h
index 23dde52..fe2a23b 100644
--- a/include/asm-arm/mmu.h
+++ b/include/asm-arm/mmu.h
@@ -7,6 +7,7 @@
 #if __LINUX_ARM_ARCH__ >= 6
 	unsigned int id;
 #endif
+	unsigned int kvm_seq;
 } mm_context_t;
 
 #if __LINUX_ARM_ARCH__ >= 6