serial: sh-sci: Fix up pretty name printing for port IRQs.

Presently these were all using the same static string with no regard to
dev_name() and the like. This implements a bit of rework to name the IRQ
dynamically, as it should have been doing all along anyways.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
diff --git a/include/linux/serial_sci.h b/include/linux/serial_sci.h
index 4ca130a..8bffe9a 100644
--- a/include/linux/serial_sci.h
+++ b/include/linux/serial_sci.h
@@ -56,6 +56,8 @@
 	SCIx_TXI_IRQ,
 	SCIx_BRI_IRQ,
 	SCIx_NR_IRQS,
+
+	SCIx_MUX_IRQ = SCIx_NR_IRQS,	/* special case */
 };
 
 enum {
@@ -82,6 +84,11 @@
 	[SCIx_BRI_IRQ]	= (irq),	\
 }
 
+#define SCIx_IRQ_IS_MUXED(port)			\
+	((port)->cfg->irqs[SCIx_ERI_IRQ] ==	\
+	 (port)->cfg->irqs[SCIx_RXI_IRQ]) ||	\
+	((port)->cfg->irqs[SCIx_ERI_IRQ] &&	\
+	 !(port)->cfg->irqs[SCIx_RXI_IRQ])
 /*
  * SCI register subset common for all port types.
  * Not all registers will exist on all parts.