rtlwifi: remove rtl_get_tid_h

'rtl_get_tid_h()' is the same as 'ieee80211_get_tid()'.
So this function can be removed to save a line of code.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/db340a67a95c119e4f9ba8fa99aea1c73d0dcfc9.1617383263.git.christophe.jaillet@wanadoo.fr