cmake: set supported language the right way

the second param of enable_launage() is not used, we should call it
multiple times to enable more than one language. switch to project()
command for simplicity.

also, define the PROJECT_VERSION using project() command, and switch to
it in the config-h.in.cmake

Signed-off-by: Kefu Chai <kchai@redhat.com>

CMakeLists.txt

@@ -1,6 +1,8 @@
 cmake_minimum_required(VERSION 2.8.11)
 
-project(ceph)
+project(ceph
+  VERSION 12.1.2
+  LANGUAGES CXX C ASM)
 set(VERSION 12.1.2)
 
 if(POLICY CMP0046)

src/CMakeLists.txt

@@ -1,6 +1,5 @@
 include(GetGitRevisionDescription)
 
-enable_language(C ASM)
 include(GNUInstallDirs)
 # for erasure and compressor plugins
 set(CMAKE_INSTALL_PKGLIBDIR ${CMAKE_INSTALL_LIBDIR}/${PROJECT_NAME})

src/include/config-h.in.cmake

@@ -293,7 +293,7 @@
 #cmakedefine HAVE_STATIC_CAST
 
 /* Version number of package */
-#cmakedefine VERSION "@VERSION@"
+#cmakedefine VERSION "@PROJECT_VERSION@"
 
 /* Defined if pthread_setname_np() is available */
 #cmakedefine HAVE_PTHREAD_SETNAME_NP 1