drivers: net: replace UINT64_MAX with U64_MAX

U64_MAX is well defined now while the UINT64_MAX is not, so we fall
back to drivers' own definition as below:

	#ifndef UINT64_MAX
	#define UINT64_MAX             (u64)(~((u64)0))
	#endif

I believe this is in one phy driver then copied and pasted to other phy
drivers.

Replace the UINT64_MAX with U64_MAX to clean up the source code.

Signed-off-by: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/dsa/mv88e6xxx/chip.c b/drivers/net/dsa/mv88e6xxx/chip.c
index 8f92ccc..a13a700 100644
--- a/drivers/net/dsa/mv88e6xxx/chip.c
+++ b/drivers/net/dsa/mv88e6xxx/chip.c
@@ -665,13 +665,13 @@ static uint64_t _mv88e6xxx_get_ethtool_stat(struct mv88e6xxx_chip *chip,
 	case STATS_TYPE_PORT:
 		err = mv88e6xxx_port_read(chip, port, s->reg, &reg);
 		if (err)
-			return UINT64_MAX;
+			return U64_MAX;
 
 		low = reg;
 		if (s->size == 4) {
 			err = mv88e6xxx_port_read(chip, port, s->reg + 1, &reg);
 			if (err)
-				return UINT64_MAX;
+				return U64_MAX;
 			high = reg;
 		}
 		break;
@@ -685,7 +685,7 @@ static uint64_t _mv88e6xxx_get_ethtool_stat(struct mv88e6xxx_chip *chip,
 			mv88e6xxx_g1_stats_read(chip, reg + 1, &high);
 		break;
 	default:
-		return UINT64_MAX;
+		return U64_MAX;
 	}
 	value = (((u64)high) << 16) | low;
 	return value;