CMake: restore IMATH_INCLUDE_DIRS include for APPLE/arm64

For some reason arm64 still requires the include directories,
update CMake accordingly.

source/blender/imbuf/CMakeLists.txt

@@ -88,6 +88,15 @@ set(LIB
 )
 
 if(WITH_IMAGE_OPENEXR)
+  # Keep until APPLE/ARM libraries are updated.
+  if(APPLE)
+    if(CMAKE_OSX_ARCHITECTURES MATCHES arm64)
+      list(APPEND INC_SYS
+        ${IMATH_INCLUDE_DIRS}
+      )
+    endif()
+  endif()
+
   list(APPEND LIB
     bf_imbuf_openexr
   )

source/blender/imbuf/intern/oiio/CMakeLists.txt

@@ -36,6 +36,15 @@ if(WITH_PUGIXML)
 endif()
 
 if(WITH_IMAGE_OPENEXR)
+  # Keep until APPLE/ARM libraries are updated.
+  if(APPLE)
+    if(CMAKE_OSX_ARCHITECTURES MATCHES arm64)
+      list(APPEND INC_SYS
+        ${IMATH_INCLUDE_DIRS}
+      )
+    endif()
+  endif()
+
   list(APPEND INC_SYS
     ${OPENEXR_INCLUDE_DIRS}
   )