net: stmmac: add flexible PPS to dwmac 4.10a

All the registers and the functionalities used in the callback
dwmac5_flex_pps_config() are common between dwmac 4.10a [1] and
5.00a [2].

Reuse the same callback for dwmac 4.10a too.

Tested on STM32MP15x, based on dwmac 4.10a.

[1] DWC Ethernet QoS Databook 4.10a October 2014
[2] DWC Ethernet QoS Databook 5.00a September 2017
Signed-off-by: Antonio Borneo <antonio.borneo@st.com>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>

drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c

@@ -938,6 +938,7 @@ const struct stmmac_ops dwmac4_ops = {
 	.pcs_get_adv_lp = dwmac4_get_adv_lp,
 	.debug = dwmac4_debug,
 	.set_filter = dwmac4_set_filter,
+	.flex_pps_config = dwmac5_flex_pps_config,
 	.set_mac_loopback = dwmac4_set_mac_loopback,
 	.update_vlan_hash = dwmac4_update_vlan_hash,
 	.sarc_configure = dwmac4_sarc_configure,