add a help text for BLK_DEV_GENERIC

This fixes kernel Bugzilla #4933.

Signed-off-by: Adrian Bunk <bunk@stusta.de>
diff --git a/drivers/ide/Kconfig b/drivers/ide/Kconfig
index ec03341..6adf864 100644
--- a/drivers/ide/Kconfig
+++ b/drivers/ide/Kconfig
@@ -383,6 +383,9 @@
 config BLK_DEV_GENERIC
 	tristate "Generic PCI IDE Chipset Support"
 	depends on BLK_DEV_IDEPCI
+        help
+          This option provides generic support for various PCI IDE Chipsets
+          which otherwise might not be supported.
 
 config BLK_DEV_OPTI621
 	tristate "OPTi 82C621 chipset enhanced support (EXPERIMENTAL)"