msm: camera: common: create a common root folder for debugfs

Create common root folder under debugfs root named camera at probe. Add
utility functions to create subdirectories under the common camera root.

CRs-Fixed: 3093049
Change-Id: Ia4cefb5d2263ecabf1b9d70deefa1ee624b04f07
Signed-off-by: Anand Ravi <quic_ananravi@quicinc.com>

drivers/camera_main.c

@@ -288,6 +288,8 @@ static int camera_init(void)
 	if (rc)
 		goto end_init;
 
+	cam_debugfs_init();
+
 	/* For Probing all available submodules */
 	for (i = 0; i < ARRAY_SIZE(submodule_table); i++) {
 		num_inits = submodule_table[i].num_component;
@@ -316,6 +318,7 @@ end_init:
 static void camera_exit(void)
 {
 	__camera_exit(ARRAY_SIZE(submodule_table), 0);
+	cam_debugfs_deinit();
 
 	CAM_INFO(CAM_UTIL, "Spectra camera driver exited!");
 }