msm: implement ARCH_RANDOM

Currently, the software random number generator is not intialized
until relatively late in the boot process. Software that relies on
random numbers early will not be reliable. Entropy sources are
available early but not early enough for some use cases which means
that moving the software random number generation earlier is not an
option. As an alternate solution, implement the functions associated
with CONFIG_ARCH_RANDOM. These functions currently make a call into
trustzone to get reliable random numbers. The functions are disabled
once the regular random number generator is sufficiently reliable.

Change-Id: If40cfcb96b091fa26a28047c10a902287b26f6c1
CRs-Fixed: 498392
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>

Conflicts:
	arch/arm/mach-msm/Makefile
arm: Add ARCH_RANDOM Kconfig

Activate Random

init: Move stack canary initialization after setup_arch

Stack canary intialization involves getting a random number.
Getting this random number may involve accessing caches or other
architectural specific features which are not available until
after the architecture is setup. Move the stack canary initialization
later to accomodate this.

Change-Id: I00b564a2c3172229a44339c061fa380c17fe7d8e
CRs-Fixed: 498392
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>

Some boards may support architecture generated random numbers. Add
the appropriate Kconfig.

Change-Id: I0077a982c9bb6d3a35435cc27fe40b7e0596ca84
CRs-Fixed: 498392
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>