Remove own_id global variable from SP deployments

Move own_id to local namespace as both ffarpc_call_ep and ffarpc_caller
dependency on global own_id has been resolved.

Signed-off-by: Imre Kis <imre.kis@arm.com>
Change-Id: I86b68a4a05285763218a9e60d6e4d4877b322707
diff --git a/deployments/protected-storage/common/ps_sp.c b/deployments/protected-storage/common/ps_sp.c
index 9b55e9a..2859dba 100644
--- a/deployments/protected-storage/common/ps_sp.c
+++ b/deployments/protected-storage/common/ps_sp.c
@@ -14,7 +14,6 @@
 #include <sp_rxtx.h>
 #include <trace.h>
 
-uint16_t own_id = 0;
 static uint8_t tx_buffer[4096] __aligned(4096);
 static uint8_t rx_buffer[4096] __aligned(4096);
 
@@ -28,6 +27,7 @@
 	struct sp_msg resp_msg = { 0 };
 	struct secure_storage_provider secure_storage_provider;
 	struct storage_backend *storage_backend;
+	uint16_t own_id = 0;
 
 	/* Boot */
 	(void) init_info;