resources, gpu-compute: fix compiler bug with Pennant

Pennant's Makefile fails when attempting to compile it without having
specified the path to the compiler.  This commit fixes that.

Change-Id: I02291ae73d41509ea6102236a5d9f4e4645c659f
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5-resources/+/51969
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Reviewed-by: Matt Sinclair <mattdsinclair@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: Jason Lowe-Power <power.jg@gmail.com>
diff --git a/src/gpu/pennant/Makefile b/src/gpu/pennant/Makefile
index 14fec63..246e419 100644
--- a/src/gpu/pennant/Makefile
+++ b/src/gpu/pennant/Makefile
@@ -1,3 +1,4 @@
+HIP_PATH ?= /opt/rocm/bin
 BUILDDIR := build
 PRODUCT := pennant
 
@@ -20,7 +21,7 @@
 # begin compiler-dependent flags
 #
 # gcc flags:
-CXX := hipcc #g++
+CXX := $(HIP_PATH)/hipcc #g++
 CXXFLAGS_DEBUG := -g
 CXXFLAGS_OPT := -O3 #-mcpu=native
 CXXFLAGS_OPENMP := #-fopenmp
@@ -45,7 +46,7 @@
 
 # end compiler-dependent flags
 
-CUDAC := hipcc 
+CUDAC := $(HIP_PATH)/hipcc
 CUDACFLAGS := #--generate-code arch=compute_60,code=sm_60 --ptxas-options=-v
 CUDACFLAGS_DEBUG := -G -lineinfo
 CUDACFLAGS_OPT := -O3