cmake remove circular linking and reorganize

- px4_add_module now requires MAIN
 - px4_add_library doesn't automatically link

src/lib/version/CMakeLists.txt

@@ -64,13 +64,13 @@ add_custom_command(OUTPUT ${px4_git_ver_header}
 set_source_files_properties(${px4_git_ver_header} PROPERTIES GENERATED TRUE)
 add_custom_target(ver_gen ALL DEPENDS ${px4_git_ver_header})
 
-px4_add_module(
-	MODULE lib__version
-	COMPILE_FLAGS
-	SRCS
-		version.c
-	DEPENDS
-		ver_gen
-		platforms__common
-	)
+# The URL for the elf file for crash logging
+if (DEFINED ENV{BUILD_URI})
+	set(BUILD_URI $ENV{BUILD_URI})
+else()
+	set(BUILD_URI "localhost")
+endif()
 
+add_definitions(-DBUILD_URI=${BUILD_URI})
+
+px4_add_library(version version.c ${px4_git_ver_header})