ANDROID: GKI: enable CONFIG_LEDS_TRIGGER_TIMER

Set CONFIG_LEDS_TRIGGER_TIMER=y to enable the "timer" trigger for the
LED subsystem. This creates the sysfs parameters "delay_on" and
"delay_off" for LEDs, which can then be used to specify a blinking
pattern for them.

Bug: 163765274
Change-Id: I66ada688aa5026253e76588ae1d6d85eb4cd8536
Signed-off-by: Guru Das Srinagesh <gurus@codeaurora.org>
[fixed up arm64 config location as it was incorrect - gregkh]
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>