Make the entry point argument optional in load_image()

There are cases where the entry point information is useless to the
caller, e.g. when an image just needs to be loaded in memory but won't
ever be executed.

This patch allows load_image() function to take a NULL pointer as the
entry point argument. In this case, it won't be populated.

Change-Id: Ie9394b054457706c6699926c5e0206e0c3851c56
Make system register functions inline assembly

Replace the current out-of-line assembler implementations of
the system register and system instruction operations with
inline assembler.

This enables better compiler optimisation and code generation
when accessing system registers.

Fixes ARM-software/tf-issues#91

Change-Id: I149af3a94e1e5e5140a3e44b9abfc37ba2324476
Provide cm_get/set_context() for current CPU

All callers of cm_get_context() pass the calling CPU MPIDR to the
function. Providing a specialised version for the current
CPU results in a reduction in code size and better readability.

The current function has been renamed to cm_get_context_by_mpidr()
and the existing name is now used for the current-CPU version.

The same treatment has been done to cm_set_context(), although
only both forms are used at present in the PSCI and TSPD code.

Change-Id: I91cb0c2f7bfcb950a045dbd9ff7595751c0c0ffb
Make the BL3-1 crash reporting optional

This patch makes the console crash dump of processor register
state optional based on the CRASH_REPORTING make variable.

This defaults to only being enabled for DEBUG builds. This can
be overridden by setting a different value in the platform
makefile or on the make command line.

Change-Id: Icfa1b2d7ff0145cf0a85e8ad732f9cee7e7e993f
Merge pull request #128 from sandrine-bailleux/sb/make-load_image-ep-optional

Make the entry point argument optional in load_image()
Merge pull request #130 from athoelke/at/inline-asm-sysreg-v2

Make system register functions inline assembly v2
Merge pull request #131 from athoelke/at/cm_get_context

Provide cm_get/set_context() for current CPU
Merge pull request #133 from athoelke/at/crash-reporting-opt

Make the BL3-1 crash reporting optional