ARM: 6134/1: Handle instruction cache maintenance fault properly

Between "clean D line..." and "invalidate I line" operations in
v7_coherent_user_range(), the memory page may get swapped out.
And the fault on "invalidate I line" could not be properly handled
causing the oops.

In ARMv6 "external abort on linefetch" replaced by "instruction cache
maintenance fault". Let's handle it as translation fault. It fixes the
issue.

I'm not sure if it's reasonable to check arch version in run-time.
Let's do it in compile time for now.

Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Siarhei Siamashka <siarhei.siamashka@nokia.com>
Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>