plat: fix switch statements to comply with MISRA rules

Ensure (where possible) that switch statements in plat comply with MISRA
rules 16.1 - 16.7.

Change-Id: Ie4a7d2fd10f6141c0cfb89317ea28a755391622f
Signed-off-by: Jonathan Wright <jonathan.wright@arm.com>
diff --git a/plat/rockchip/rk3368/plat_sip_calls.c b/plat/rockchip/rk3368/plat_sip_calls.c
index 7383d2f..03fee88 100644
--- a/plat/rockchip/rk3368/plat_sip_calls.c
+++ b/plat/rockchip/rk3368/plat_sip_calls.c
@@ -19,9 +19,6 @@
 				   void *handle,
 				   uint64_t flags)
 {
-	switch (smc_fid) {
-	default:
-		ERROR("%s: unhandled SMC (0x%x)\n", __func__, smc_fid);
-		SMC_RET1(handle, SMC_UNK);
-	}
+	ERROR("%s: unhandled SMC (0x%x)\n", __func__, smc_fid);
+	SMC_RET1(handle, SMC_UNK);
 }