wlan_platform: Add CONFIG_CNSS_OUT_OF_TREE flag

Use CONFIG_CNSS_OUT_OF_TREE to control if ICNSS family drivers are
built from in-kernel-tree source or out-of-kernel-tree source since
the exposed header files will be in different paths. This is also
for backward compatibility.
Resolve ICNSS compilation issue with msm-5.15 kernel.

Change-Id: I0a94f70c1be659a00f9401e57ee1dd31b6aa82ae

icnss2/main.h

@@ -10,7 +10,11 @@
 #include <linux/kobject.h>
 #include <linux/platform_device.h>
 #include <linux/ipc_logging.h>
+#ifdef CONFIG_CNSS_OUT_OF_TREE
+#include "icnss2.h"
+#else
 #include <soc/qcom/icnss2.h>
+#endif
 #include "wlan_firmware_service_v01.h"
 #include <linux/mailbox_client.h>
 

icnss2/qmi.c

@@ -22,9 +22,11 @@
 #include <linux/firmware.h>
 #include <linux/soc/qcom/qmi.h>
 #include <linux/platform_device.h>
+#ifdef CONFIG_CNSS_OUT_OF_TREE
+#include "icnss2.h"
+#else
 #include <soc/qcom/icnss2.h>
-#include <soc/qcom/service-locator.h>
-#include <soc/qcom/service-notifier.h>
+#endif
 #include <soc/qcom/of_common.h>
 #include "wlan_firmware_service_v01.h"
 #include "main.h"