mxs: reorganize source directory for easy sharing of code in i.MXS SoCs

Most code can be shared between i.MX23 and i.MX28 as both are from
i.MXS family; this source directory structure makes easy to share code
among them.

Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>
Acked-by: Stefano Babic <sbabic@denx.de>
diff --git a/doc/README.m28 b/doc/README.m28
index 7dee8ce..2a92226 100644
--- a/doc/README.m28
+++ b/doc/README.m28
@@ -4,8 +4,8 @@
 Files of the M28/M28EVK port
 ----------------------------
 
-arch/arm/cpu/arm926ejs/mx28/	- The CPU support code for the Freescale i.MX28
-arch/arm/include/asm/arch-mx28/	- Header files for the Freescale i.MX28
+arch/arm/cpu/arm926ejs/mxs/	- The CPU support code for the Freescale i.MX28
+arch/arm/include/asm/arch-mxs/	- Header files for the Freescale i.MX28
 board/denx/m28evk/		- M28EVK board specific files
 include/configs/m28evk.h	- M28EVK configuration file