leds: ns2: do not guard OF match pointer with of_match_ptr

Do not match OF match pointer with of_match_ptr, so that even if
CONFIG_OF is disabled, the driver can still be bound via another method.

Move definition of of_ns2_leds_match just before ns2_led_driver
definition, since it is not needed sooner.

Signed-off-by: Marek Behún <kabel@kernel.org>
Tested-by: Simon Guinot <simon.guinot@sequanux.org>
Signed-off-by: Pavel Machek <pavel@ucw.cz>