1. Cleanup unused code in startup.c.
2. Init MMU before init INT contoroller for mapping vector table to visual address 0x0
3. Remove unused section in link scripts.
2. [bsp][sam9260] Modify SCONS scripts to support IAR tool chain.
3. [bsp][sam9260] Move link strips in to folder link_scripts.
4. [libcpu][arm926] Add copy right to source file and format code.