DCE-KMD: Make certain util functions static

- This is a follow-up CL to address comment from
  I42bfe95aa81823dc077ae0964eb6288a1f25fc17

- Certain utils functions are used in single files so make
  them static and move to files in which they are used.

- Rename these from dce_os*() to dce_().

- Delete dce_get_fw_phy_addr() as it's unused.

JIRA TDS-16126

Change-Id: I6049ae1d381ac9c18acbcd3b2584d4d8ab3f2dc0
Signed-off-by: anupamg <anupamg@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/c/linux-nv-oot/+/3248435
Reviewed-by: Mahesh Kumar <mahkumar@nvidia.com>
Reviewed-by: Arun Swain <arswain@nvidia.com>
GVS: buildbot_gerritrpt <buildbot_gerritrpt@nvidia.com>
Reviewed-by: svcacv <svcacv@nvidia.com>

drivers/platform/tegra/dce/dce-debug.c

@@ -15,6 +15,18 @@
 #include <interface/dce-interface.h>
 #include <interface/dce-core-interface-errors.h>
 
+/**
+ * dce_get_fw_name - Gets the dce fw name from platform data.
+ *
+ * @d : Pointer to tegra_dce struct.
+ *
+ * Return : fw_name
+ */
+static const char *dce_get_fw_name(struct tegra_dce *d)
+{
+	return pdata_from_dce(d)->fw_name;
+}
+
 /**
  * dbg_dce_load_fw - loads the fw to DRAM.
  *
@@ -24,7 +36,7 @@
  */
 static int dbg_dce_load_fw(struct tegra_dce *d)
 {
-	const char *name = dce_os_get_fw_name(d);
+	const char *name = dce_get_fw_name(d);
 
 	d->fw_data = dce_os_request_firmware(d, name);
 	if (!d->fw_data) {