kconfig: use bool instead of boolean for type definition attributes

Support for keyword 'boolean' will be dropped later on.

No functional change.

Reference: http://lkml.kernel.org/r/cover.1418003065.git.cj@linux.com
Signed-off-by: Christoph Jaeger <cj@linux.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>

drivers/net/wireless/rt2x00/Kconfig

@@ -243,14 +243,14 @@ config RT2X00_LIB
 	select AVERAGE
 
 config RT2X00_LIB_FIRMWARE
-	boolean
+	bool
 	select FW_LOADER
 
 config RT2X00_LIB_CRYPTO
-	boolean
+	bool
 
 config RT2X00_LIB_LEDS
-	boolean
+	bool
 	default y if (RT2X00_LIB=y && LEDS_CLASS=y) || (RT2X00_LIB=m && LEDS_CLASS!=n)
 
 config RT2X00_LIB_DEBUGFS