leds: aw2013_led: fix issue led->vdd/vcc is NULL

kernel panic from as the led->vdd passed from the aw2013_power_on is NULL
hence panic. vdd/vcc instance are only assigned to red led, need to use the
led instance in pdata to make sure the vdd/vcc instances are valid.

Change-Id: I908feffa52194b5f4502200bf13e911e0ddbb933
Signed-off-by: Mao Li <maol@codeaurora.org>