[RETRY] Support autoboot feature in uboot for fastmodel

  I) Add how to use for u-boot autoboot feature in README.md
	1. Download CodeBendch Lite Compiler for u-boot
	2. Testing Hypervisor Prototype 2 automatically with u-boot
 II) Summary of u-boot_fastmodel.patch
	1. add 'vexpress_rtsm_ca15' to u-boot/boards.cfg
	2. add include/configs/vexpress_rtsm_ca15.h and add include/configs/vexpress_rtsm_common.h
		you want to test the patch, you can see as the above I-2