console: move search_device() from iomux.h to console.h

search_device() is defined in console.c. Move its declaration
to an appropriate header file.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/include/console.h b/include/console.h
index 58a4ec3..4e06b13 100644
--- a/include/console.h
+++ b/include/console.h
@@ -25,6 +25,8 @@
 int disable_ctrlc(int);	/* 1 to disable, 0 to enable Control-C detect */
 int confirm_yesno(void);        /*  1 if input is "y", "Y", "yes" or "YES" */
 
+struct stdio_dev *search_device(int flags, const char *name);
+
 #ifdef CONFIG_CONSOLE_RECORD
 /**
  * console_record_init() - set up the console recording buffers