fix(plat/mediatek/mt8195): fix coverity fail

Add break to correct the driver flow.

Change-Id: Ie20f402d543fbf90172671e007fad30d5dc2ab10
diff --git a/plat/mediatek/mt8195/drivers/spm/mt_spm_vcorefs.c b/plat/mediatek/mt8195/drivers/spm/mt_spm_vcorefs.c
index 2a9a789..6a85b5c 100644
--- a/plat/mediatek/mt8195/drivers/spm/mt_spm_vcorefs.c
+++ b/plat/mediatek/mt8195/drivers/spm/mt_spm_vcorefs.c
@@ -465,13 +465,17 @@
 	switch (gear) {
 	case 3:
 		ret_val = vcore_opp_0_uv;
+		break;
 	case 2:
 		ret_val = vcore_opp_1_uv;
+		break;
 	case 1:
 		ret_val = vcore_opp_2_uv;
+		break;
 	case 0:
 	default:
 		ret_val = vcore_opp_3_uv;
+		break;
 	}
 	return ret_val;
 }