refactor(psa): change all occurrences of RSS to RSE

Changes all occurrences of "RSS" and "rss" in the code and build files
to "RSE" and "rse".

Signed-off-by: Tamas Ban <tamas.ban@arm.com>
Change-Id: I606e2663fb3719edf6372d6ffa4f1982eef45994
diff --git a/lib/psa/measured_boot_private.h b/lib/psa/measured_boot_private.h
index b8ca31d..bf2ae48 100644
--- a/lib/psa/measured_boot_private.h
+++ b/lib/psa/measured_boot_private.h
@@ -13,8 +13,8 @@
 #include <drivers/measured_boot/metadata.h>
 
 /* Measured boot message types that distinguish its services */
-#define RSS_MEASURED_BOOT_READ		1001U
-#define RSS_MEASURED_BOOT_EXTEND	1002U
+#define RSE_MEASURED_BOOT_READ		1001U
+#define RSE_MEASURED_BOOT_EXTEND	1002U
 
 struct measured_boot_read_iovec_in_t {
     uint8_t index;