ARM: 8640/1: Add support for CONFIG_DEBUG_VIRTUAL

ARM: 8640/1: Add support for CONFIG_DEBUG_VIRTUAL

x86 has an option: CONFIG_DEBUG_VIRTUAL to do additional checks on
virt_to_phys calls. The goal is to catch users who are calling
virt_to_phys on non-linear addresses immediately. This includes caller
using __virt_to_phys() on image addresses instead of __pa_symbol(). This
is a generally useful debug feature to spot bad code (particulary in
drivers).

Acked-by: Russell King <[email protected]>
Acked-by: Laura Abbott <[email protected]>
Signed-off-by: Florian Fainelli <[email protected]>
Signed-off-by: Russell King <[email protected]>