Optee a80 porting

Optee-os add a80 platform support.

This request have three patchs, The patchs summary:
1.gic driver add gic_cpu_init function, mainly for secondary cpu secure stage initialization,
2.Make uart driver more portable, add common console.h and console basic functions,
3.Add plat-sunxi support, the initial version, running on A80 Optimus board.

All patchs only tested on A80 Optimus board, Due to the lack of platform.
Mayeb the uart driver patch should be test on vexpress platform.
I think the command " TEESMC32_ST_FASTCALL_GET_SHM_CONFIG"  should be a general system command, not platform specific command for STM. because every platform will provide the same function to get platform share memory information.
So " TEESMC32_ST_FASTCALL_GET_SHM_CONFIG"  should be move from teesmc_st.h to teesmc.h, and rename as " TEESMC32_FASTCALL_GET_SHM_CONFIG". If modify like this, Avoid every platform copy and paste teesmc_st.h.