refactor(plat/imx/imx): make imx io-storage logic for TBBR/FIP common

This commit makes imx image io-storage logic common for all
imx platform.

Signed-off-by: Ying-Chun Liu (PaulLiu) <paulliu@debian.org>
Change-Id: I15045ac8f9dfa8cb714e32f9e7475d5eae4e86e4
diff --git a/plat/imx/imx7/include/imx7_def.h b/plat/imx/imx7/include/imx7_def.h
index 77a8ca3..d92a2d1 100644
--- a/plat/imx/imx7/include/imx7_def.h
+++ b/plat/imx/imx7/include/imx7_def.h
@@ -13,7 +13,7 @@
 /*******************************************************************************
  * Function and variable prototypes
  ******************************************************************************/
-void plat_imx7_io_setup(void);
+void plat_imx_io_setup(void);
 void imx7_platform_setup(u_register_t arg1, u_register_t arg2,
 			 u_register_t arg3, u_register_t arg4);