build: use $CELL_SDK and fall back to $CELL_SDK if not set.

configure.ac

@@ -99,12 +99,16 @@ AC_CHECK_LIB(sysmodule_stub, cellSysmoduleLoadModule,
   dnl  For PSGL
   AC_DEFINE(HAVE_GLES_2X, 1, Define to 1 if GLES 2.x is available) # FIXME: hack
   GL_LIBS="${GL_LIBS} -lPSGL -lgcm_cmd -lgcm_sys_stub"
+  dnl  This is the old way
+  if test "x${CELLSDK}" != x -a "x${CELLSDK}" = x; then
+    CELL_SDK="${CELLSDK}"
+  fi
   if test "x${enable_debug}" = xyes; then
-    GL_LIBS="${GL_LIBS} -L${CELLSDK}/target/ppu/lib/PSGL/RSX/debug"
+    GL_LIBS="${GL_LIBS} -L${CELL_SDK}/target/ppu/lib/PSGL/RSX/debug"
   elif test "x${enable_release}" = xyes; then
-    GL_LIBS="${GL_LIBS} -L${CELLSDK}/target/ppu/lib/PSGL/RSX/ultra-opt"
+    GL_LIBS="${GL_LIBS} -L${CELL_SDK}/target/ppu/lib/PSGL/RSX/ultra-opt"
   else
-    GL_LIBS="${GL_LIBS} -L${CELLSDK}/target/ppu/lib/PSGL/RSX/opt"
+    GL_LIBS="${GL_LIBS} -L${CELL_SDK}/target/ppu/lib/PSGL/RSX/opt"
   fi
   dnl  For the runtime Cg compiler
   GL_LIBS="${GL_LIBS} -lcgc -lPSGLcgc"