Kconfig: Fix Kconfig for Intel ixgbe and igb PTP support.

Fix Kconfig file to make sure that PTP and IGB/IXGBE are both either
in-kernel or modules, not mixed.  Having the build status mixed causes
compile errors.
Signed-off-by: Carolyn Wyborny <carolyn.wyborny@intel.com>
Tested-by: Jeff Pieper <jeffrey.e.pieper@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/Kconfig

@@ -122,8 +122,10 @@ config IGB_DCA
 
 config IGB_PTP
 	bool "PTP Hardware Clock (PHC)"
-	default y
-	depends on IGB && PTP_1588_CLOCK
+	default n
+	depends on IGB && EXPERIMENTAL
+	select PPS
+	select PTP_1588_CLOCK
 	---help---
 	  Say Y here if you want to use PTP Hardware Clock (PHC) in the
 	  driver.  Only the basic clock operations have been implemented.
@@ -223,7 +225,9 @@ config IXGBE_DCB
 config IXGBE_PTP
 	bool "PTP Clock Support"
 	default n
-	depends on IXGBE && PTP_1588_CLOCK
+	depends on IXGBE && EXPERIMENTAL
+	select PPS
+	select PTP_1588_CLOCK
 	---help---
 	  Say Y here if you want support for 1588 Timestamping with a
 	  PHC device, using the PTP 1588 Clock support. This is