wifi: rtlwifi: simplify LED management

Introduce 'rtl_init_sw_leds()' to replace per-chip LED
initialization code (and so drop 'struct rtl_led' as no
longer used), drop 'init_sw_leds' and 'deinit_sw_leds'
fields from 'struct rtl_hal_ops', adjust related code.

Signed-off-by: Dmitry Antipov <dmantipov@yandex.ru>
Acked-by: Ping-Ke Shih <pkshih@realtek.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20230614061832.40882-1-dmantipov@yandex.ru