meson: Move config file creation out of executable block

The configuration file generation within the executable block does not
define the necessary macros. Moving the configuration_file() outside the
executable block creates proper cofig.h file

Change-Id: I43fc5115a47f36a265268acef5e518959ee5be37
Signed-off-by: Deepa Karthikeyan <deepakala.karthikeyan@ibm.com>
diff --git a/meson.build b/meson.build
index 261191b..c543a6b 100644
--- a/meson.build
+++ b/meson.build
@@ -96,6 +96,8 @@
     extra_deps = []
 endif
 
+configure_file(output: 'config.h', configuration: conf_data)
+
 deps = [
     systemd,
     sdbusplus_dep,
@@ -106,7 +108,6 @@
 
 executable('watchdog_timeout',
     'watchdog_timeout.cpp',
-    configure_file(output: 'config.h', configuration: conf_data),
     generated_sources,
     dependencies: deps,
     link_with: watchdog_lib,