Remove GMAC algorithm (for now)

It can't be implemented with the current version of the API
diff --git a/include/psa/crypto_values.h b/include/psa/crypto_values.h
index 472ad38..2c0acf3 100644
--- a/include/psa/crypto_values.h
+++ b/include/psa/crypto_values.h
@@ -845,7 +845,6 @@
 #define PSA_ALG_CBC_MAC                         ((psa_algorithm_t)0x02c00001)
 /** The CMAC construction over a block cipher */
 #define PSA_ALG_CMAC                            ((psa_algorithm_t)0x02c00002)
-#define PSA_ALG_GMAC                            ((psa_algorithm_t)0x02c00003)
 
 /** Whether the specified algorithm is a MAC algorithm based on a block cipher.
  *
diff --git a/library/psa_crypto.c b/library/psa_crypto.c
index 2285694..5245e61 100644
--- a/library/psa_crypto.c
+++ b/library/psa_crypto.c
@@ -2005,8 +2005,6 @@
     }
     else if( alg == PSA_ALG_CMAC )
         mode = MBEDTLS_MODE_ECB;
-    else if( alg == PSA_ALG_GMAC )
-        mode = MBEDTLS_MODE_GCM;
     else
         return( NULL );
 
diff --git a/tests/suites/test_suite_psa_crypto_metadata.data b/tests/suites/test_suite_psa_crypto_metadata.data
index b011ad5..f5d5a33 100644
--- a/tests/suites/test_suite_psa_crypto_metadata.data
+++ b/tests/suites/test_suite_psa_crypto_metadata.data
@@ -150,18 +150,6 @@
 depends_on:MBEDTLS_DES_C:MBEDTLS_CMAC_C
 mac_algorithm:PSA_ALG_CMAC:ALG_IS_BLOCK_CIPHER_MAC:8:PSA_KEY_TYPE_DES:192
 
-MAC: GMAC-AES-128
-depends_on:MBEDTLS_AES_C:MBEDTLS_GCM_C
-mac_algorithm:PSA_ALG_GMAC:ALG_IS_BLOCK_CIPHER_MAC:16:PSA_KEY_TYPE_AES:128
-
-MAC: GMAC-AES-192
-depends_on:MBEDTLS_AES_C:MBEDTLS_GCM_C
-mac_algorithm:PSA_ALG_GMAC:ALG_IS_BLOCK_CIPHER_MAC:16:PSA_KEY_TYPE_AES:192
-
-MAC: GMAC-AES-256
-depends_on:MBEDTLS_AES_C:MBEDTLS_GCM_C
-mac_algorithm:PSA_ALG_GMAC:ALG_IS_BLOCK_CIPHER_MAC:16:PSA_KEY_TYPE_AES:256
-
 Cipher: ARC4
 depends_on:MBEDTLS_ARC4_C
 cipher_algorithm:PSA_ALG_ARC4:ALG_IS_STREAM_CIPHER