hif_bus_prevent_linkdown() calls to cnss_wlan_pm_control(), which
is only defined when CONFIG_PCI_MSM is enabled, fix the conditional
compilation.
Also fix a typo of RUNTIME_PM to FEATURE_RUNTIME_PM.
Change-Id: I9d4cd65ee0020ca1b41d026c3124317ce854ea92
CRs-fixed: 966771