corstone1000: Pin layer SHAs for blacksail release

Pin the Corstone-1000 kas layer revisions for the Blacksail release.

Set the default repository branch to blacksail and pin bitbake,
openembedded-core, meta-yocto, meta-openembedded, and meta-secure-core.

Signed-off-by: Harsimran Singh Tungal <harsimransingh.tungal@arm.com>
Signed-off-by: Jon Mason <jon.mason@arm.com>

kas/corstone1000-base.yml

@@ -5,21 +5,25 @@ distro: poky
 
 defaults:
   repos:
-    branch: master
+    branch: blacksail
 
 repos:
   bitbake:
     url: https://git.openembedded.org/bitbake
+    branch: "2.20"
+    commit: 634f8dede6b9d71b5a6691499fd05a8678b46eae
     layers:
       bitbake: disabled
 
   core:
     url: https://git.openembedded.org/openembedded-core
+    commit: e182a0c4b91fd459c1f9dece0c7c23f7f9eaa7ab
     layers:
       meta:
 
   meta-yocto:
     url: https://git.yoctoproject.org/meta-yocto
+    commit: d0119aa2eb77b985fcd33ac527d5c0287eb68e58
     layers:
       meta-poky:
 
@@ -31,7 +35,7 @@ repos:
 
   meta-openembedded:
     url: https://git.openembedded.org/meta-openembedded
-    # commit: 461d85a1831318747af5abe86da193bcde3fd9b4
+    commit: a9d69bc066bf9498397db27902c287dd666fdfd4
     layers:
       meta-oe:
       meta-python:
@@ -39,7 +43,8 @@ repos:
 
   meta-secure-core:
     url: https://github.com/wind-river/meta-secure-core.git
-    # commit: 59d7e90542947c342098863b9998693ac79352b0
+    branch: master
+    commit: 56316bacdb3e79defca52ff016a406daa8034c67
     layers:
       meta-secure-core-common:
       meta-signing-key: