refactor(qemu): 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: I2c6840f6f3f2f8f64595a0e0aa6e12084a37ce6e
diff --git a/plat/qemu/common/qemu_plat_attest_token.c b/plat/qemu/common/qemu_plat_attest_token.c
index cf3376d..f7d7e90 100644
--- a/plat/qemu/common/qemu_plat_attest_token.c
+++ b/plat/qemu/common/qemu_plat_attest_token.c
@@ -98,7 +98,7 @@
 
 /*
  * Get the hardcoded platform attestation token as QEMU does not support
- * RSS.
+ * RSE.
  */
 int plat_rmmd_get_cca_attest_token(uintptr_t buf, size_t *len,
 				   uintptr_t hash, size_t hash_size)