docs: Update Release information for v2.5

Updated tentative code freeze and release target date
for v2.5 release.

Change-Id: Idcfd9a127e9210846370dfa0685badac5b1c25c7
Signed-off-by: Manish V Badarkhe <Manish.Badarkhe@arm.com>

docs/about/release-information.rst

@@ -44,6 +44,8 @@ depending on project requirement and partner feedback.
 +-----------------+---------------------------+------------------------------+
 | v2.4            | 2nd week of Nov '20       | 4th week of Oct '20          |
 +-----------------+---------------------------+------------------------------+
+| v2.5            | 2nd week of May '21       | 4th week of Apr '21          |
++-----------------+---------------------------+------------------------------+
 
 Removal of Deprecated Interfaces
 --------------------------------