ARM: shmobile: Fix device node reference leakage in shmobile_init_delay

The of_find_compatible_node() function returns a new reference to the
found node. Instead of just adding of_node_put() calls, simplify the
code by moving the CPU identification logic inside the loop over cpu
nodes, in order to lower complexity from O(n) to O(1) by replacing
of_find_compatible_node() calls with of_device_is_compatible().

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Magnus Damm <damm+renesas@opensource.se>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>