Fix build issues with bit_extract sample

Change-Id: I628b3c83a16f7adf0ab8ca60aecde8c073c34fd9


[ROCm/hip commit: 935e3cd649]

projects/hip/samples/0_Intro/bit_extract/Makefile

@@ -11,10 +11,6 @@ HIPCC=$(HIP_PATH)/bin/hipcc
 ifeq (${HIP_PLATFORM}, nvcc)
 	HIPCC_FLAGS = -gencode=arch=compute_20,code=sm_20 
 endif
-ifeq (${HIP_PLATFORM}, hcc)
-	HIPCC_FLAGS = -stdlib=libc++
-endif
-
 
 EXE=bit_extract