boards: arm: mimxrt1060_evk: added additional PWM outputs

Added PWM outputs to arduino header, to make testing PWM support with
this EVK simpler. These PWM outputs are enabled by the pwm_api test,
although they are not used. The user can enable the PWM shell in order
to test these PWM outputs.

Signed-off-by: Daniel DeGrasse <daniel.degrasse@nxp.com>