xtensa: xtfpga: use CONFIG_USE_OF instead of CONFIG_OF

Use platform data to initialize xtfpga device drivers when CONFIG_USE_OF
is not selected. This fixes xtfpga networking when CONFIG_USE_OF is not
selected but CONFIG_OF is.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

arch/xtensa/platforms/xtfpga/setup.c

@@ -66,7 +66,7 @@ void __init platform_calibrate_ccount(void)
 
 #endif
 
-#ifdef CONFIG_OF
+#ifdef CONFIG_USE_OF
 
 static void __init xtfpga_clk_setup(struct device_node *np)
 {
@@ -284,4 +284,4 @@ static int __init xtavnet_init(void)
  */
 arch_initcall(xtavnet_init);
 
-#endif /* CONFIG_OF */
+#endif /* CONFIG_USE_OF */