octeontx2-pf: Reduce minimum mtu size to 60

PTP messages like SYNC, FOLLOW_UP, DELAY_REQ are of size 58 bytes.
Using a minimum packet length as 64 makes NIX to pad 6 bytes of
zeroes while transmission. This is causing latest ptp4l application to
emit errors since length in PTP header and received packet are not same.
Padding upto 3 bytes is fine but more than that makes ptp4l to assume
the pad bytes as a TLV. Hence reduce the size to 60 from 64.
Signed-off-by: NSubbaraya Sundeep <sbhatta@marvell.com>
Signed-off-by: NNaveen Mamindlapalli <naveenm@marvell.com>
Signed-off-by: NSunil Kovvuri Goutham <sgoutham@marvell.com>
Link: https://lore.kernel.org/r/20220729092457.3850-1-naveenm@marvell.comSigned-off-by: NJakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/marvell/octeontx2/nic/otx2_txrx.h

@@ -21,7 +21,7 @@
 #define OTX2_HEAD_ROOM		OTX2_ALIGN
 
 #define	OTX2_ETH_HLEN		(VLAN_ETH_HLEN + VLAN_HLEN)
-#define	OTX2_MIN_MTU		64
+#define	OTX2_MIN_MTU		60
 
 #define OTX2_MAX_GSO_SEGS	255
 #define OTX2_MAX_FRAGS_IN_SQE	9