serial: cpm_uart: Fix build error without CONFIG_SERIAL_CPM_CONSOLE

drivers/tty/serial/cpm_uart/cpm_uart_core.c: In function ‘cpm_uart_init_port’:
drivers/tty/serial/cpm_uart/cpm_uart_core.c:1251:7: error: ‘udbg_port’ undeclared (first use in this function); did you mean ‘uart_port’?
  if (!udbg_port)
       ^~~~~~~~~
       uart_port

commit d142585b leave this corner, wrap it with #ifdef block

Fixes: d142585b ("serial: cpm_uart: Protect udbg definitions by CONFIG_SERIAL_CPM_CONSOLE")
Signed-off-by: NYueHaibing <yuehaibing@huawei.com>
Link: https://lore.kernel.org/r/20220518135452.39480-1-yuehaibing@huawei.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/cpm_uart/cpm_uart_core.c

@@ -1247,7 +1247,7 @@ static int cpm_uart_init_port(struct device_node *np,
 	}
 
 #ifdef CONFIG_PPC_EARLY_DEBUG_CPM
-#ifdef CONFIG_CONSOLE_POLL
+#if defined(CONFIG_CONSOLE_POLL) && defined(CONFIG_SERIAL_CPM_CONSOLE)
 	if (!udbg_port)
 #endif
 		udbg_putc = NULL;