staging: board: description for CONFIG_STAGING_BOARD

A paragraph to describe what CONFIG_STAGING_BOARD is for,
to help developers have better understanding.
Signed-off-by: Song Chen <chensong_2000@189.cn>
Link: https://lore.kernel.org/r/1608889958-32118-1-git-send-email-chensong_2000@189.cnSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/board/Kconfig

@@ -3,7 +3,10 @@ config STAGING_BOARD
 	bool "Staging Board Support"
 	depends on OF_ADDRESS && OF_IRQ && CLKDEV_LOOKUP
 	help
-	  Select to enable per-board staging support code.
-
-	  If in doubt, say N here.
+	  Staging board base is to support continuous upstream
+	  in-tree development and integration of platform devices.
 
+	  Helps developers integrate devices as platform devices for
+	  device drivers that only provide platform device bindings.
+	  This in turn allows for incremental development of both
+	  hardware feature support and DT binding work in parallel.