hwspinlock/core: simplify Kconfig

Simplify hwspinlock's Kconfig by making the global CONFIG_HWSPINLOCK
entry invisible; users will just select it when needed.

This also prepares the ground for adding hwspinlock support for other
platforms (the 'depends on ARCH_OMAP4' was rather hideous, and while
we're at it, a dedicated menu is added).
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>

drivers/hwspinlock/Kconfig

@@ -2,22 +2,20 @@
 # Generic HWSPINLOCK framework
 #
 
+# HWSPINLOCK always gets selected by whoever wants it.
 config HWSPINLOCK
-	tristate "Generic Hardware Spinlock framework"
-	depends on ARCH_OMAP4
-	help
-	  Say y here to support the generic hardware spinlock framework.
-	  You only need to enable this if you have hardware spinlock module
-	  on your system (usually only relevant if your system has remote slave
-	  coprocessors).
+	tristate
 
-	  If unsure, say N.
+menu "Hardware Spinlock drivers"
 
 config HWSPINLOCK_OMAP
 	tristate "OMAP Hardware Spinlock device"
-	depends on HWSPINLOCK && ARCH_OMAP4
+	depends on ARCH_OMAP4
+	select HWSPINLOCK
 	help
 	  Say y here to support the OMAP Hardware Spinlock device (firstly
 	  introduced in OMAP4).
 
 	  If unsure, say N.
+
+endmenu