Make CMake options for distcc and ccache more visible.

Move them from build/cmake/aom_configure.cmake to the
CMakeLists.txt at the root of the repository.

Change-Id: Ib39764abe0c3456414ba157ebc18fd7a052db0df

CMakeLists.txt

@@ -16,6 +16,9 @@ if (NOT EMSCRIPTEN)
   endif ()
 endif ()
 
+option(ENABLE_CCACHE "Enable ccache support." OFF)
+option(ENABLE_DISTCC "Enable distcc support." OFF)
+
 project(AOM C CXX)
 
 set(AOM_ROOT "${CMAKE_CURRENT_SOURCE_DIR}")

build/cmake/aom_configure.cmake

@@ -16,9 +16,6 @@ include(FindwxWidgets)
 set(AOM_SUPPORTED_CPU_TARGETS
     "arm64 armv7 armv7s generic mips32 mips64 x86 x86_64")
 
-option(ENABLE_CCACHE "Enable ccache support" OFF)
-option(ENABLE_DISTCC "Enable distcc support" OFF)
-
 # Generate the user config settings. This must occur before include of
 # aom_config_defaults.cmake (because it turns every config variable into a cache
 # variable with its own help string).