serial: ucc_uart: stub out soft_uart_init for !CONFIG_PPC32

The Soft UART hack is only needed for some PPC-based SOCs. To allow
building this driver for non-PPC, guard soft_uart_init() and its
helpers by CONFIG_PPC32, and use a no-op soft_uart_init() otherwise.
Reviewed-by: Timur Tabi <timur@kernel.org>
Acked-by: Timur Tabi <timur@kernel.org>
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Li Yang <leoyang.li@nxp.com>

drivers/tty/serial/ucc_uart.c

@@ -33,7 +33,10 @@
 
 #include <linux/firmware.h>
 #include <soc/fsl/cpm.h>
-#include <asm/reg.h>
+
+#ifdef CONFIG_PPC32
+#include <asm/reg.h> /* mfspr, SPRN_SVR */
+#endif
 
 /*
  * The GUMR flag for Soft UART.  This would normally be defined in qe.h,
@@ -1096,6 +1099,8 @@ static const struct uart_ops qe_uart_pops = {
 	.verify_port    = qe_uart_verify_port,
 };
 
+
+#ifdef CONFIG_PPC32
 /*
  * Obtain the SOC model number and revision level
  *
@@ -1238,6 +1243,16 @@ static int soft_uart_init(struct platform_device *ofdev)
 	return 0;
 }
 
+#else /* !CONFIG_PPC32 */
+
+static int soft_uart_init(struct platform_device *ofdev)
+{
+	return 0;
+}
+
+#endif
+
+
 static int ucc_uart_probe(struct platform_device *ofdev)
 {
 	struct device_node *np = ofdev->dev.of_node;