ide: introduce HAVE_IDE

To allow flexible configuration of IDE introduce HAVE_IDE.
All archs except arm, um and s390 unconditionally select it.
For arm the actual configuration determine if IDE is supported.

This is a step towards introducing drivers/Kconfig for arm.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Russell King - ARM Linux <linux@arm.linux.org.uk>
Acked-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
diff --git a/arch/alpha/Kconfig b/arch/alpha/Kconfig
index 5b7dcd5..002703b 100644
--- a/arch/alpha/Kconfig
+++ b/arch/alpha/Kconfig
@@ -5,6 +5,7 @@
 config ALPHA
 	bool
 	default y
+	select HAVE_IDE
 	select HAVE_OPROFILE
 	help
 	  The Alpha is a 64-bit general-purpose processor designed and