psa_util: rename parameter of mbedtls_ecc_group_from_psa

The new name better reflects the fact that the 1st parameter
is just the EC family and not the curve.

Signed-off-by: Valerio Setti <valerio.setti@nordicsemi.no>
diff --git a/library/psa_util.c b/library/psa_util.c
index d833299..41586e2 100644
--- a/library/psa_util.c
+++ b/library/psa_util.c
@@ -250,10 +250,10 @@
     }
 }
 
-mbedtls_ecp_group_id mbedtls_ecc_group_from_psa(psa_ecc_family_t curve,
+mbedtls_ecp_group_id mbedtls_ecc_group_from_psa(psa_ecc_family_t family,
                                                 size_t bits)
 {
-    switch (curve) {
+    switch (family) {
         case PSA_ECC_FAMILY_SECP_R1:
             switch (bits) {
 #if defined(PSA_WANT_ECC_SECP_R1_192)