nrf_security: Add pk.c from Oberon PSA and not MbedTLS

Use the pk.c file from the Oberon PSA core instead of the
MbedTLS. Oberon copied this file to their repo because of
it manually defines the PSA_EXPORT_KEY_PAIR_OR_PUBLIC_MAX_SIZE
which is already defined by the Oberon PSA core.

The file in the Oberon PSA repo is the same with the MbedTLS
3.6.2 version apart from the removal of this define.

Signed-off-by: Georgios Vasilakis <georgios.vasilakis@nordicsemi.no>

Author: Vge0rge

subsys/nrf_security/src/CMakeLists.txt

@@ -80,12 +80,16 @@ if(NOT CONFIG_MBEDTLS_PSA_CRYPTO_SPM AND NOT BUILD_INSIDE_TFM)
     cipher.c
     cipher_wrap.c
     md.c
-    pk.c
     pk_ecc.c
     pk_wrap.c
     pkwrite.c
     psa_util.c
   )
+
+  # Oberon copied this file to avoid double definition of PSA_EXPORT_KEY_PAIR_OR_PUBLIC_MAX_SIZE
+  append_with_prefix(src_crypto ${OBERON_PSA_CORE_PATH}/programs/ssl/library
+    pk.c
+  )
 endif()
 
 # Library for mbed TLS crypto toolbox functionality