wifi: ath12k: wmi: delete PSOC_HOST_MAX_NUM_SS

Both PSOC_HOST_MAX_NUM_SS and WMI_MAX_NUM_SS are set to 8. The host assumes
that the values are the same but there's no check for that, so things will
break if either of the values change. It's simpler and safer to have just one
define so delete PSOC_HOST_MAX_NUM_SS and use WMI_MAX_NUM_SS everywhere.

No functional changes.

Tested-on: WCN7850 hw2.0 PCI WLAN.HMT.1.0-03427-QCAHMTSWPL_V1.0_V2.0_SILICONZ-1.15378.4

Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://lore.kernel.org/r/20221220120655.19389-4-kvalo@kernel.org