Fix installing generated header to include/include

This isn't the ideal solution, but a lot more cleanups are needed for
how install is used.

Change-Id: I63a9c1a46d0da13ee4373038ece228005207271a

CMakeLists.txt

@@ -461,7 +461,7 @@ endif()
 
 # Install generated headers
 # FIXME: Associate with individual targets.
-install(DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/include
+install(DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/include/hip
   DESTINATION include
   FILES_MATCHING PATTERN "*.h*")