IMX: MX31: Cleanup include files and drop nasty #ifdef in drivers

As exception among the i.MX processors, the i.MX31 has headers
without general names (mx31-regs.h, mx31.h instead of imx-regs.h and
clock.h). This requires several nasty #ifdef in the drivers to
include the correct header. The patch cleans up the driver and
renames the header files as for the other i.MX processors.

Signed-off-by: Stefano Babic <sbabic@denx.de>
diff --git a/include/configs/imx31_litekit.h b/include/configs/imx31_litekit.h
index 5023638..9405f56 100644
--- a/include/configs/imx31_litekit.h
+++ b/include/configs/imx31_litekit.h
@@ -28,7 +28,7 @@
 #ifndef __CONFIG_H
 #define __CONFIG_H
 
-#include <asm/arch/mx31-regs.h>
+#include <asm/arch/imx-regs.h>
 
  /* High Level Configuration Options */
 #define CONFIG_ARM1136		1    /* This is an arm1136 CPU core */