EFR32: DeviceAttestationCredentialsProvider implemented. (#20005)

* EFR32: DeviceAttestationCredentialsProvider implemented.

* EFR32: DeviceAttestationCredentialsProvider: Review comments applied.

* EFR32: DeviceAttestationCredentialsProvider: Review comments applied.
diff --git a/src/lib/lib.gni b/src/lib/lib.gni
index c78be22..213592c 100644
--- a/src/lib/lib.gni
+++ b/src/lib/lib.gni
@@ -20,4 +20,7 @@
   # a Commissioner or Administrator that employs different or more complex
   # logic, this should be set to false.
   chip_build_default_attestation_verifier = true
+
+  # Set to true to enable device-specific attestation credentials
+  chip_build_platform_attestation_credentials_provider = false
 }