Docs: Create a dedicated sub-folder for TF-M Profiles

Create a sub-folder profiles under design_documents to hold all
TF-M Profiles design documents.
Update the links.

Change-Id: Ida124c417c8fddb4d88b34bdac5dac8a5db9f966
Signed-off-by: David Hu <david.hu@arm.com>
diff --git a/docs/design_documents/symmetric_initial_attest.rst b/docs/design_documents/symmetric_initial_attest.rst
index afd2fd2..00642b8 100644
--- a/docs/design_documents/symmetric_initial_attest.rst
+++ b/docs/design_documents/symmetric_initial_attest.rst
@@ -588,7 +588,7 @@
 
 .. [1] `PSA Attestation API 1.0 (ARM IHI 0085) <https://developer.arm.com/-/media/Files/pdf/PlatformSecurityArchitecture/Implement/IHI0085-PSA_Attestation_API-1.0.2.pdf?revision=eef78753-c77e-4b24-bcf0-65596213b4c1&la=en&hash=E5E0353D612077AFDCE3F2F3708A50C77A74B2A3>`_
 
-.. [2] :doc:`Trusted Firmware-M Profile Small Design </docs/design_documents/tfm_profile_small>`
+.. [2] :doc:`Trusted Firmware-M Profile Small Design </docs/design_documents/profiles/tfm_profile_small>`
 
 .. [3] :doc:`Initial Attestation Service Integration Guide </docs/reference/services/tfm_attestation_integration_guide>`