feat(lfa): create LFA SMC handler template

As per the specification v1.0[1], added all Live Firmware Activation
(LFA) SMCs, including their Function IDs (FIDs) and associated error
codes.
A dummy handler function has been created as a template. Subsequent
patches will implement the handling of these SMCs.

[1]: https://developer.arm.com/documentation/den0147/latest/

Signed-off-by: Manish V Badarkhe <Manish.Badarkhe@arm.com>
Change-Id: I5d6500dcff35aa4a438cd5f97f349cd57406ddce
diff --git a/docs/getting_started/build-options.rst b/docs/getting_started/build-options.rst
index e80f3d1..9d2df33 100644
--- a/docs/getting_started/build-options.rst
+++ b/docs/getting_started/build-options.rst
@@ -1497,6 +1497,9 @@
    per the `PSA Crypto API specification`_. This feature is only supported if
    using MbedTLS 3.x version. It is disabled (``0``) by default.
 
+-  ``LFA_SUPPORT``: Boolean flag to enable support for Live Firmware
+   activation as per the specification. This option defaults to 0.
+
 -  ``TRANSFER_LIST``: Setting this to ``1`` enables support for Firmware
    Handoff using Transfer List defined in `Firmware Handoff specification`_.
    This defaults to ``0``. Current implementation follows the Firmware Handoff