Revert "imgtool: Add backwards compatibility for ECDSA"

This reverts commit 78135ee6eb6759ea009442d7f9bcec6bbe6934ef
as bba5a711483447d7eee2531b65bd1c07c81746c9 made it unnecessary.

Change-Id: Idee755f05c17502599aaa947826e9a7feb08b4a7
Signed-off-by: David Vincze <david.vincze@arm.com>
diff --git a/scripts/imgtool/main.py b/scripts/imgtool/main.py
index b8b2e49..eba557f 100755
--- a/scripts/imgtool/main.py
+++ b/scripts/imgtool/main.py
@@ -362,8 +362,6 @@
               help='send to OUTFILE the payload or payload''s digest instead '
               'of complied image. These data can be used for external image '
               'signing')
-@click.option('--legacy-ecdsa-tlv', default=False, is_flag=True,
-              help='Use the old curve specific ECDSA TLV')
 @click.command(help='''Create a signed or unsigned image\n
                INFILE and OUTFILE are parsed as Intel HEX if the params have
                .hex extension, otherwise binary format is used''')
@@ -372,7 +370,7 @@
          endian, encrypt_keylen, encrypt, infile, outfile, dependencies,
          load_addr, hex_addr, erased_val, save_enctlv, security_counter,
          boot_record, custom_tlv, rom_fixed, max_align, clear, fix_sig,
-         fix_sig_pubkey, sig_out, vector_to_sign, legacy_ecdsa_tlv):
+         fix_sig_pubkey, sig_out, vector_to_sign):
 
     if confirm:
         # Confirmed but non-padded images don't make much sense, because
@@ -439,7 +437,7 @@
 
     img.create(key, public_key_format, enckey, dependencies, boot_record,
                custom_tlvs, int(encrypt_keylen), clear, baked_signature,
-               pub_key, vector_to_sign, legacy_ecdsa_tlv)
+               pub_key, vector_to_sign)
     img.save(outfile, hex_addr)
 
     if sig_out is not None: