armv7a_mmu: Remove warning on va = pa

armv7a_mmu: Remove warning on va = pa

Depending on how the MMU is configured it is possible to have a 1:1
mapping between virtual and physical addresses, thus making this warning
bogus. We already check that the MMU is enabled in the caller:
cortex_a_virt2phys().

Change-Id: I09f4c53ef933c8d1e268da5215a769449be014bc
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-on: http://openocd.zylin.com/5007
Tested-by: jenkins
Reviewed-by: Antonio Borneo <borneo.antonio@gmail.com>
Reviewed-by: Kamal Dasu <kdasu.kdev@gmail.com>
Reviewed-by: Matthias Welwarsky <matthias@welwarsky.de>