Add or remove theme support custom post type

/**
 * Enables the Excerpt meta box in Page edit screen.
 */
function wpcodex_add_excerpt_support_for_pages() {
	add_post_type_support( 'page', 'excerpt' );
}
add_action( 'init', 'wpcodex_add_excerpt_support_for_pages' );

function my_custom_init() {
	remove_post_type_support( 'post', 'excerpt' );
}
add_action( 'init', 'my_custom_init' );