docs: add load address relative offset node

When this is provided in the partition manifest, it should be added to
the load address to get the base address of the region.

Signed-off-by: Davidson K <davidson.kumaresan@arm.com>
Change-Id: Ib6d3d6a29af0a3eb87fac67c58220ba25342e1cd
diff --git a/docs/components/ffa-manifest-binding.rst b/docs/components/ffa-manifest-binding.rst
index 29b89b2..c5dad14 100644
--- a/docs/components/ffa-manifest-binding.rst
+++ b/docs/components/ffa-manifest-binding.rst
@@ -228,6 +228,14 @@
      then communicate the region properties (including the base address chosen
      by the partition manager) to the partition.
 
+- load-address-relative-offset
+   - value type: <u64>
+   - Offset relative to the load address of the partition.
+     When this is provided in the partition manifest, it should be added to the
+     load address to get the base address of the region. The secure partition
+     manifest can have either "base-address" or "load-address-relative-offset".
+     It cannot have both.
+
 - stream-ids
    - value type: <prop-encoded-array>
    - List of IDs belonging to a DMA capable peripheral device that has access to