serial: omap: Support debug UART

Add debug UART functions to permit omap specific ns16550 to
provide an early debug UART. This is mostly in common with
DEBUG_UART_NS16550 except for Mode definition register which
is required for selecting UART mode(16x auto-baud or 13x mode).

Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Tom Rini <trini@konsulko.com>
diff --git a/include/debug_uart.h b/include/debug_uart.h
index 2980ae6..6f0b0c5 100644
--- a/include/debug_uart.h
+++ b/include/debug_uart.h
@@ -111,6 +111,17 @@
 #define _DEBUG_UART_ANNOUNCE
 #endif
 
+#define serial_dout(reg, value)	\
+	serial_out_shift((char *)com_port + \
+		((char *)reg - (char *)com_port) * \
+			(1 << CONFIG_DEBUG_UART_SHIFT), \
+		CONFIG_DEBUG_UART_SHIFT, value)
+#define serial_din(reg) \
+	serial_in_shift((char *)com_port + \
+		((char *)reg - (char *)com_port) * \
+			(1 << CONFIG_DEBUG_UART_SHIFT), \
+		CONFIG_DEBUG_UART_SHIFT)
+
 /*
  * Now define some functions - this should be inserted into the serial driver
  */