IOMUX: Split out for_each_console_dev() helper macro

It is not only less lines of code, but also better readability
when new macro is being in use. Introduce for_each_console_dev()
helper macro and convert current users to it.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
diff --git a/include/iomux.h b/include/iomux.h
index 9c2d579..bd4a143 100644
--- a/include/iomux.h
+++ b/include/iomux.h
@@ -24,6 +24,11 @@
  */
 extern int cd_count[MAX_FILES];
 
+#define for_each_console_dev(i, file, dev)		\
+	for (i = 0, dev = console_devices[file][i];	\
+	     i < cd_count[file];			\
+	     i++, dev = console_devices[file][i])
+
 int iomux_match_device(struct stdio_dev **, const int, struct stdio_dev *);
 int iomux_doenv(const int, const char *);
 void iomux_printdevs(const int);