net: CNSS: Define new config WLAN_FEATURE_RX_WAKELOCK

qcom_rx_wakelock needs to be acquired to prevent device from
going in suspend state while running throughput when USB is
disconnected with LCD off.

Define new config WLAN_FEATURE_RX_WAKELOCK to enable feature
based macro in wlan host driver and subsequently initialize
qcom_rx_wakelock.

Change-Id: Ic06fadc2293247a8237e426b479ce82c7dd39ede
CRs-Fixed: 971578
Signed-off-by: Himanshu Agarwal <himanaga@codeaurora.org>