realtek: pcs: rtl931x: call CMU config from hw mode config

One deviating piece left is the extra call in 931x's setup_serdes to
config_cmu. It is called right after the hw mode configuration, in
contrast to 930x. Until we find a better home, move it to the end of
config_hw_mode to retain behavior but to pave the way for the final
unification steps.

Link: https://github.com/openwrt/openwrt/pull/23861
Signed-off-by: Jonas Jelonek <jelonek.jonas@gmail.com>

target/linux/realtek/files-6.18/drivers/net/pcs/pcs-rtl-otto.c

@@ -3852,7 +3852,7 @@ static int rtpcs_931x_sds_config_hw_mode(struct rtpcs_serdes *sds,
 		return -ENOTSUPP;
 	}
 
-	return 0;
+	return rtpcs_93xx_sds_config_cmu(sds, hw_mode);
 }
 
 static int rtpcs_931x_setup_serdes(struct rtpcs_serdes *sds,
@@ -3864,10 +3864,6 @@ static int rtpcs_931x_setup_serdes(struct rtpcs_serdes *sds,
 	if (ret < 0)
 		return ret;
 
-	ret = rtpcs_93xx_sds_config_cmu(sds, hw_mode);
-	if (ret < 0)
-		return ret;
-
 	return 0;
 }