crypto/x509: Rename v3_{skey,skid}.c, v3_{akey,akid}.c, v3_{alt,san}.c

Reviewed-by: Tomas Mraz <tmraz@fedoraproject.org>
(Merged from https://github.com/openssl/openssl/pull/13658)

crypto/x509/build.info

@@ -9,7 +9,7 @@ SOURCE[../../libcrypto]=\
         x_crl.c t_crl.c x_req.c t_req.c x_x509.c t_x509.c \
         x_pubkey.c x_x509a.c x_attrib.c x_exten.c x_name.c \
         v3_bcons.c v3_bitst.c v3_conf.c v3_extku.c v3_ia5.c v3_utf8.c v3_lib.c \
-        v3_prn.c v3_utl.c v3err.c v3_genn.c v3_alt.c v3_skey.c v3_akey.c \
+        v3_prn.c v3_utl.c v3err.c v3_genn.c v3_san.c v3_skid.c v3_akid.c \
         v3_pku.c v3_int.c v3_enum.c v3_sxnet.c v3_cpols.c v3_crld.c v3_purp.c \
         v3_info.c v3_akeya.c v3_pmaps.c v3_pcons.c v3_ncons.c \
         v3_pcia.c v3_pci.c v3_ist.c \