platform/x86: x86-android-tablets: Add "select LEDS_CLASS"

Since the x86-android-tablets now calls devm_led_classdev_register_ext()
it needs to select LEDS_CLASS as well as LEDS_CLASS' NEW_LEDS dependency.

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202405182256.FsKBjIzG-lkp@intel.com/
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20240521094741.273397-1-hdegoede@redhat.com