wifi: ath12k: fix missing endianness conversion in wmi_vdev_create_cmd()

The WMI commands are in little endian byte order, fix missing endianness
conversion in wmi_vdev_create_cmd.

Tested-on: WCN7850 hw2.0 WLAN.IOE_HMT.1.0.2-00240-QCAHMTSWPL_V1.0_V2.0_SILICON-1

Signed-off-by: Miaoqing Pan <quic_miaoqing@quicinc.com>
Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://msgid.link/20240322003726.2016208-1-quic_miaoqing@quicinc.com