docs(ff-a): managed exit parameter separation

As of DEN0077A FF-A v1.1 Beta0 section 5.2, managed exit
support is moved out of messaging-method field and is described in a
separate field.

Signed-off-by: Maksims Svecovs <maksims.svecovs@arm.com>
Change-Id: Icb12d9dc0d10b11c105dc1920e5212b0359af147
diff --git a/docs/components/ffa-manifest-binding.rst b/docs/components/ffa-manifest-binding.rst
index 437df67..df2985c 100644
--- a/docs/components/ffa-manifest-binding.rst
+++ b/docs/components/ffa-manifest-binding.rst
@@ -110,10 +110,13 @@
    - Specifies which messaging methods are supported by the partition, set bit
      means the feature is supported, clear bit - not supported:
 
-      - Bit[0]: support for receiving direct message requests
-      - Bit[1]: support for sending direct messages
-      - Bit[2]: support for indirect messaging
-      - Bit[3]: support for managed exit
+      - Bit[0]: partition can receive direct requests if set
+      - Bit[1]: partition can send direct requests if set
+      - Bit[2]: partition can send and receive indirect messages
+
+- managed-exit
+   - value type: <empty>
+   - Specifies if managed exit is supported.
 
 - has-primary-scheduler
    - value type: <empty>