FogBugz #166933: Fixed OCRAM false double bit error

Ensure the stack pointer memory region is initialized during the
early run of the Preloader and U-Boot. This is to avoid the false
double bit error which might occurred during stack access. It is
due to the OCRAM controller always read in 64 bits manner. This issue
is spotted when we switch to new Altera version GNU toolchain.

Signed-off-by: Chin Liang See <clsee@altera.com>
FogBugz #158875: Enhance Preloader and U-Boot to use THUMB2

This is to enhance the Preloader and U-Boot to smaller size by
using THUMB2 mode. With smaller size, it will yield better boot
time as the flash accessing took most of the boot time.

Signed-off-by: Chin Liang See <clsee@altera.com>
---
Changes for v2
- Fixed the commit message
FogBugz #158875: Enhance semihosting code for THUMB2 mode

Enhance the semihosting code where we will using different
SVC value for THUMB mode.

Signed-off-by: Chin Liang See <clsee@altera.com>