resources: fix Makefile for lulesh

The LULESH Makefile did not include the path to the hipcc
compiler, which caused it to fail when compiling.  This patch
fixes this by adding in HIP_PATH, which can optionally be
overridden by the users having already set it.

Change-Id: I28f890ee220a25276aff7ccc524a596e7268ec42
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5-resources/+/50947
Reviewed-by: Bobby R. Bruce <bbruce@ucdavis.edu>
Maintainer: Bobby R. Bruce <bbruce@ucdavis.edu>
Tested-by: Bobby R. Bruce <bbruce@ucdavis.edu>
diff --git a/src/gpu/lulesh/Makefile b/src/gpu/lulesh/Makefile
index 64bdc4f..fbe0642 100755
--- a/src/gpu/lulesh/Makefile
+++ b/src/gpu/lulesh/Makefile
@@ -1,7 +1,8 @@
-BIN_DIR?= ./bin
+BIN_DIR ?= ./bin
+HIP_PATH ?= /opt/rocm/hip
 
 all: $(BIN_DIR)
-	hipcc src/lulesh.hip.cc -o $(BIN_DIR)/lulesh --amdgpu-target=gfx801
+	$(HIP_PATH)/bin/hipcc src/lulesh.hip.cc -o $(BIN_DIR)/lulesh --amdgpu-target=gfx801
 
 $(BIN_DIR):
 	mkdir -p $(BIN_DIR)