ARM: pxa: don't select RFKILL if CONFIG_NET is disabled

Bluetooth is only supported when network support is part of the kernel,
so it is a bit pointless to build the tosa-bt support without networking.
If we try anyway, we get a Kconfig warning:

warning: (TOSA_BT && H1940BT) selects RFKILL which has unmet direct dependencies (NET)

This adds a dependency on CONFIG_NET to avoid that case.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>

arch/arm/mach-pxa/Kconfig

@@ -528,7 +528,7 @@ config MACH_TOSA
 
 config TOSA_BT
 	tristate "Control the state of built-in bluetooth chip on Sharp SL-6000"
-	depends on MACH_TOSA
+	depends on MACH_TOSA && NET
 	select RFKILL
 	help
 	  This is a simple driver that is able to control