Enable third party contributions

- Add instructions for contributing to ARM Trusted Firmware.

- Update copyright text in all files to acknowledge contributors.

Change-Id: I9311aac81b00c6c167d2f8c889aea403b84450e5
diff --git a/bl2/aarch64/bl2_arch_setup.c b/bl2/aarch64/bl2_arch_setup.c
index ed457ee..6283c1c 100644
--- a/bl2/aarch64/bl2_arch_setup.c
+++ b/bl2/aarch64/bl2_arch_setup.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013, ARM Limited. All rights reserved.
+ * Copyright (c) 2013, ARM Limited and Contributors. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
diff --git a/bl2/aarch64/bl2_entrypoint.S b/bl2/aarch64/bl2_entrypoint.S
index 0255d65..75970f7 100644
--- a/bl2/aarch64/bl2_entrypoint.S
+++ b/bl2/aarch64/bl2_entrypoint.S
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013, ARM Limited. All rights reserved.
+ * Copyright (c) 2013, ARM Limited and Contributors. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
diff --git a/bl2/bl2.ld.S b/bl2/bl2.ld.S
index 7e9e5a5..dee138c 100644
--- a/bl2/bl2.ld.S
+++ b/bl2/bl2.ld.S
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013, ARM Limited. All rights reserved.
+ * Copyright (c) 2013, ARM Limited and Contributors. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
diff --git a/bl2/bl2.mk b/bl2/bl2.mk
index 212aa92..f36b7bb 100644
--- a/bl2/bl2.mk
+++ b/bl2/bl2.mk
@@ -1,5 +1,5 @@
 #
-# Copyright (c) 2013, ARM Limited. All rights reserved.
+# Copyright (c) 2013, ARM Limited and Contributors. All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are met:
diff --git a/bl2/bl2_main.c b/bl2/bl2_main.c
index aae67b4..c738677 100644
--- a/bl2/bl2_main.c
+++ b/bl2/bl2_main.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013, ARM Limited. All rights reserved.
+ * Copyright (c) 2013, ARM Limited and Contributors. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met: