dm: serial: Introduce ->getinfo() callback

New callback will give a necessary information to fill up ACPI SPCR table,
for example. Maybe used later for other purposes.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Change ADR_SPACE_SYSTEM_IO to SERIAL_ADDRESS_SPACE_IO to fix build error:
Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/serial/sandbox.c b/drivers/serial/sandbox.c
index 76d26d3..33102fc 100644
--- a/drivers/serial/sandbox.c
+++ b/drivers/serial/sandbox.c
@@ -188,6 +188,26 @@
 	return 0;
 }
 
+static int sandbox_serial_getinfo(struct udevice *dev,
+				  struct serial_device_info *serial_info)
+{
+	struct serial_device_info info = {
+		.type = SERIAL_CHIP_UNKNOWN,
+		.addr_space = SERIAL_ADDRESS_SPACE_IO,
+		.addr = SERIAL_DEFAULT_ADDRESS,
+		.reg_width = 1,
+		.reg_offset = 0,
+		.reg_shift = 0,
+	};
+
+	if (!serial_info)
+		return -EINVAL;
+
+	*serial_info = info;
+
+	return 0;
+}
+
 #if CONFIG_IS_ENABLED(OF_CONTROL)
 static const char * const ansi_colour[] = {
 	"black", "red", "green", "yellow", "blue", "megenta", "cyan",
@@ -221,6 +241,7 @@
 	.getc = sandbox_serial_getc,
 	.getconfig = sandbox_serial_getconfig,
 	.setconfig = sandbox_serial_setconfig,
+	.getinfo = sandbox_serial_getinfo,
 };
 
 static const struct udevice_id sandbox_serial_ids[] = {