The firmware advertises the LDPC support information for HT in
HT capability info in the wmi service ready event. To provide
granularity, firmware now advertises WMI_HT_CAP_RX_LDPC and
WMI_HT_CAP_TX_LDPC separately. To support LDPC, host should
also check for WMI_HT_CAP_RX_LDPC and WMI_HT_CAP_TX_LDPC in HT
capabilities.

Add a condition to existing logic in host to know whether firmware
supports LDPC or not.

Tested HW: WCN3990
Tested FW: WLAN.HL.3.1-00784-QCAHLSWMTPLZ-1,
           WLAN.HL.2.0-01617-QCAHLSWMTPLZ-1
Signed-off-by: Surabhi Vishnoi <svishnoi@codeaurora.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>