Mark another target as PHONY

Test: fewer warnings with --warn_real_to_phony turned on for Kati
Change-Id: Ifca6110d856aeda92b10c68e21bc93e2a6f372fe
diff --git a/CtsCoverage.mk b/CtsCoverage.mk
index 8a0eef8..3f54cb3 100644
--- a/CtsCoverage.mk
+++ b/CtsCoverage.mk
@@ -94,7 +94,7 @@
 .PHONY: cts-combined-xml-coverage
 cts-combined-xml-coverage : $(cts-combined-xml-coverage-report)
 
-.PHONY: cts-api-coverage
+.PHONY: cts-coverage-report-all cts-api-coverage
 cts-coverage-report-all: cts-test-coverage cts-verifier-coverage cts-combined-coverage cts-combined-xml-coverage
 
 # Put the test coverage report in the dist dir if "cts-api-coverage" is among the build goals.