util/cbfstool/amdcompress: fix short option for maxsize

Both the help and the maxsize option had the same short option character
assigned. Change the short option for maxsize to m to fix this and to
make it consistent with the rest of the code.

Change-Id: Icac1a7d4906345c37a5c7bed2b4995fea25f860e
Signed-off-by: Felix Held <felix-coreboot@felixheld.de>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/47574
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-by: Marshall Dawson <marshalldawson3rd@gmail.com>

util/cbfstool/amdcompress.c

@@ -30,7 +30,7 @@ static struct option long_options[] = {
 	{"infile",           required_argument, 0, 'i' },
 	{"outfile",          required_argument, 0, 'o' },
 	{"compress",         required_argument, 0, 'c' },
-	{"maxsize",          required_argument, 0, 'h' },
+	{"maxsize",          required_argument, 0, 'm' },
 	{"uncompress",       required_argument, 0, 'u' },
 	{"help",             no_argument,       0, 'h' },
 };