Make /dev/port conditional on config symbol

Instead of having /dev/port support dependent in multiple places on a
string of preprocessor symbols, define a new configuration directive for
it.  This ensures that all four places remain consistent with each other.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/char/Kconfig b/drivers/char/Kconfig
index a26d917..eeb5d96 100644
--- a/drivers/char/Kconfig
+++ b/drivers/char/Kconfig
@@ -1071,5 +1071,11 @@
 	  /sys/devices/platform/telco_clock, with a number of files for
 	  controlling the behavior of this hardware.
 
+config DEVPORT
+	bool
+	depends on !M68K
+	depends on ISA || PCI
+	default y
+
 endmenu