net: ec_bhf: Add runtime dependencies

The ec_bhf driver is specific to the Beckhoff CX embedded PC series.
These are based on Intel x86 CPU. So we can add a dependency on
X86, with COMPILE_TEST as an alternative to still allow for broader
build-testing.
Signed-off-by: NJean Delvare <jdelvare@suse.de>
Cc: Darek Marcinkiewicz <reksio@newterm.pl>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/Kconfig

@@ -39,6 +39,7 @@ source "drivers/net/ethernet/cisco/Kconfig"
 config CX_ECAT
 	tristate "Beckhoff CX5020 EtherCAT master support"
 	depends on PCI
+	depends on X86 || COMPILE_TEST
 	---help---
 	  Driver for EtherCAT master module located on CCAT FPGA
 	  that can be found on Beckhoff CX5020, and possibly other of CX