wifi: rtw89: fill STBC and LDPC capabilities to TX descriptor

Fill STBC and LDPC fields to get better performance when transmitting under
noisy environment. Old chips like 8852AE use firmware command to enable
these two capabilities, but newer chips must use TX descriptor.

Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Link: https://msgid.link/20240522023830.9798-1-pkshih@realtek.com