Add FontAwesome Icon to Search Form Input Button

functions.php

<?php
// Do NOT add the PHP opening tag

// Add Icon Fonts to theme
add_action( 'wp_enqueue_scripts', 'rs_enqueue_styles' );
function rs_enqueue_styles() {
	
	wp_enqueue_style( 'fa', '//maxcdn.bootstrapcdn.com/font-awesome/4.5.0/css/font-awesome.min.css', array(), '4.5' );
	
}

// Add search icon to Genesis search form input button
add_filter( 'genesis_search_button_text', 'rs_search_button_text' );
function rs_search_button_text( $text ) {
	
	return esc_attr( '&#xf002;' );
}