rtl8xxxu: Add rtl8xxxu_auto_llt_table()

Newer chips can auto load the LLT table, it is no longer necessary to
build it manually in the driver.

Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>