leds: leds-ipaq-micro: Use devm_led_classdev_register

Use of resource-managed function devm_led_classdev_register
instead of led_classdev_register is preferred, consequently
remove redundant function micro_leds_remove.

Signed-off-by: Muhammad Falak R Wani <falakreyaz@gmail.com>
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>