meson: switch config.h to config.hpp

Enable a transition of this file from C to C++ so that we
can use C++ constants instead of #defines in future commits.

Change-Id: I1149ebdaaeb99b7e7974ca846b9b07a3399edea0
Signed-off-by: Delphine CC Chiu <Delphine_CC_Chiu@wiwynn.com>
Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
diff --git a/meson.build b/meson.build
index 49b2d45..8c0405c 100644
--- a/meson.build
+++ b/meson.build
@@ -37,7 +37,7 @@
 conf_data.set('LOOKUP_GPIO_BASE', get_option('lookup-gpio-base').allowed())
 conf_data.set('ENABLE_RESET_BUTTON_DO_WARM_REBOOT', get_option('reset-button-do-warm-reboot').allowed())
 
-configure_file(output: 'config.h',
+configure_file(output: 'config.hpp',
     configuration: conf_data
 )