leds: uleds: Use module_misc_device macro to simplify the code

Use the module_misc_device macro to simplify the code, which is the
same as declaring with module_init() and module_exit().

Signed-off-by: Li Zetao <lizetao1@huawei.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20230815075944.1089298-3-lizetao1@huawei.com


Signed-off-by: Lee Jones <lee@kernel.org>