ptp: fix kconfig dependency warnings

Fix kconfig warnings:

PTP_1588_CLOCK selects NET_PTP_CLASSIFY, which depends on NET,
so PTP_1588_CLOCK should also depend on NET.

PTP_1588_CLOCK_PCH selects PTP_1588_CLOCK so the former should
depend on NET.

warning: (IXP4XX_ETH && PTP_1588_CLOCK) selects NET_PTP_CLASSIFY which has unmet direct dependencies (NET)

warning: (SFC && TILE_NET && BFIN_MAC_USE_HWSTAMP && TIGON3 && FEC && E1000E && IGB && IXGBE && I40E && MLX4_EN && SXGBE_ETH && STMMAC_ETH && TI_CPTS && PTP_1588_CLOCK_GIANFAR && PTP_1588_CLOCK_IXP46X && DP83640_PHY && PTP_1588_CLOCK_PCH) selects PTP_1588_CLOCK which has unmet direct dependencies (NET)
[This warning is caused by the new 'depends on NET' in PTP_1588_CLOCK.]
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/ptp/Kconfig

@@ -6,6 +6,7 @@ menu "PTP clock support"
 
 config PTP_1588_CLOCK
 	tristate "PTP clock support"
+	depends on NET
 	select PPS
 	select NET_PTP_CLASSIFY
 	help
@@ -74,7 +75,7 @@ config DP83640_PHY
 config PTP_1588_CLOCK_PCH
 	tristate "Intel PCH EG20T as PTP clock"
 	depends on X86 || COMPILE_TEST
-	depends on HAS_IOMEM
+	depends on HAS_IOMEM && NET
 	select PTP_1588_CLOCK
 	help
 	  This driver adds support for using the PCH EG20T as a PTP