tty: serial: amba-pl011: factor QDF2400 SoC erratum 44 out of probe

On this platform, different vendor data is used. That requires a
compile-time check as we access (1) a global boolean & (2) our local
vendor data. Both symbols are accessible only when
CONFIG_ACPI_SPCR_TABLE is enabled.

Factor the vendor data overriding to a separate function that is empty
when CONFIG_ACPI_SPCR_TABLE is not defined.
Suggested-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>
Link: https://lore.kernel.org/r/20231207-mbly-uart-v6-8-e384afa5e78c@bootlin.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/amba-pl011.c

@@ -2869,6 +2869,22 @@ static int pl011_resume(struct device *dev)
 
 static SIMPLE_DEV_PM_OPS(pl011_dev_pm_ops, pl011_suspend, pl011_resume);
 
+#ifdef CONFIG_ACPI_SPCR_TABLE
+static void qpdf2400_erratum44_workaround(struct device *dev,
+					  struct uart_amba_port *uap)
+{
+	if (!qdf2400_e44_present)
+		return;
+
+	dev_info(dev, "working around QDF2400 SoC erratum 44\n");
+	uap->vendor = &vendor_qdt_qdf2400_e44;
+}
+#else
+static void qpdf2400_erratum44_workaround(struct device *dev,
+					  struct uart_amba_port *uap)
+{ /* empty */ }
+#endif
+
 static int sbsa_uart_probe(struct platform_device *pdev)
 {
 	struct uart_amba_port *uap;
@@ -2904,13 +2920,8 @@ static int sbsa_uart_probe(struct platform_device *pdev)
 		return ret;
 	uap->port.irq	= ret;
 
-#ifdef CONFIG_ACPI_SPCR_TABLE
-	if (qdf2400_e44_present) {
-		dev_info(&pdev->dev, "working around QDF2400 SoC erratum 44\n");
-		uap->vendor = &vendor_qdt_qdf2400_e44;
-	} else
-#endif
-		uap->vendor = &vendor_sbsa;
+	uap->vendor = &vendor_sbsa;
+	qpdf2400_erratum44_workaround(&pdev->dev, uap);
 
 	uap->reg_offset	= uap->vendor->reg_offset;
 	uap->fifosize	= 32;