Deprecated EVP_PKEY_CTX_get0_dh_kdf_ukm() and EVP_PKEY_CTX_get0_ecdh_kdf_ukm()

The functions are not needed and require returning octet ptr parameters
from providers that would like to support them which complicates provider
implementations.

Fixes #12985

Reviewed-by: Paul Dale <pauli@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/14279)
diff --git a/crypto/evp/ec_ctrl.c b/crypto/evp/ec_ctrl.c
index 17f1a8f..ff0c55d 100644
--- a/crypto/evp/ec_ctrl.c
+++ b/crypto/evp/ec_ctrl.c
@@ -243,6 +243,7 @@
     return ret;
 }
 
+#ifndef OPENSSL_NO_DEPRECATED_3_0
 int EVP_PKEY_CTX_get0_ecdh_kdf_ukm(EVP_PKEY_CTX *ctx, unsigned char **pukm)
 {
     size_t ukmlen;
@@ -283,6 +284,7 @@
 
     return ret;
 }
+#endif
 
 #ifndef FIPS_MODULE
 /*