kernel: remove unused morse led trigger driver

package/base-files/files/etc/init.d/led

package/base-files/files/lib/functions/leds.sh

package/kernel/linux/modules/leds.mk

...dm5120/patches-3.18/009-adm5120_leds_switch_trigger.patch

target/linux/generic/config-3.18

target/linux/generic/config-4.1

target/linux/generic/config-4.4

target/linux/generic/files/drivers/leds/ledtrig-morse.c

target/linux/generic/patches-3.18/830-ledtrig_morse.patch

target/linux/generic/patches-3.18/831-ledtrig_netdev.patch

target/linux/generic/patches-3.18/832-ledtrig_usbdev.patch

target/linux/generic/patches-4.1/830-ledtrig_morse.patch

target/linux/generic/patches-4.1/831-ledtrig_netdev.patch

target/linux/generic/patches-4.1/832-ledtrig_usbdev.patch

target/linux/generic/patches-4.4/830-ledtrig_morse.patch

target/linux/generic/patches-4.4/831-ledtrig_netdev.patch

target/linux/generic/patches-4.4/832-ledtrig_usbdev.patch