serial: amba-pl011: move variable into CONFIG_DMA_ENGINE conditional

Variable dmacr is only used if DMA is enabled, so move it into the
CONFIG_DMA_ENGINE conditional.
Signed-off-by: Lino Sanfilippo <l.sanfilippo@kunbus.com>
Link: https://lore.kernel.org/r/20240407002709.16224-3-l.sanfilippo@kunbus.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/amba-pl011.c

@@ -256,7 +256,6 @@ struct uart_amba_port {
 	const u16		*reg_offset;
 	struct clk		*clk;
 	const struct vendor_data *vendor;
-	unsigned int		dmacr;		/* dma control reg */
 	unsigned int		im;		/* interrupt mask */
 	unsigned int		old_status;
 	unsigned int		fifosize;	/* vendor-specific */
@@ -266,6 +265,7 @@ struct uart_amba_port {
 	unsigned int		rs485_tx_drain_interval; /* usecs */
 #ifdef CONFIG_DMA_ENGINE
 	/* DMA stuff */
+	unsigned int		dmacr;		/* dma control reg */
 	bool			using_tx_dma;
 	bool			using_rx_dma;
 	struct pl011_dmarx_data dmarx;