ARM: mm: Move the idmap print to appropriate place in the code

Commit 9e9a367c29cebd2 {ARM: Section based HYP idmap} moved
the address conversion inside identity_mapping_add() without
respective print which carries useful idmap information.

Move the print as well inside identity_mapping_add() to
fix the same.

Cc: Will Deacon <will.deacon@arm.com>
Cc: Nicolas Pitre <nico@linaro.org>
Cc: Russell King <linux@arm.linux.org.uk>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>