Add option to create release build for Thunk

By adding REL=1 to the make command line (e.g. make REL=1 deb), we can
create a release build of the Thunk. This will not affect existing
functionality, and will only have an effect if REL=1 is specified on the
command line, or in the build_thunk.sh script.

Change-Id: Iedc3b6094e70a4ebd726499eda56013cc254b83d


[ROCm/ROCR-Runtime commit: cb3a664065]

projects/rocr-runtime/src/Makefile

@@ -13,7 +13,12 @@ CFLAGS += -Wformat-security -Wswitch-default -Wundef \
 	  -Wlogical-op -Wstrict-prototypes -Wmissing-prototypes    \
 	  -Wmissing-declarations -Wredundant-decls                 \
 	  -Wunreachable-code
-CFLAGS += -std=gnu99 -ggdb -pthread -fvisibility=hidden -O2
+CFLAGS += -std=gnu99 -pthread -fvisibility=hidden -O2
+
+# If this is not a release build, add debug-specific flags
+ifneq ($(REL),1)
+  CFLAGS += -ggdb
+endif
 
 LDFLAGS += -lrt -pthread -Wl,--version-script=libhsakmt.ver -Wl,-soname=$(LIB_NAME).$(LIB_MAJOR_VER)