leds: expresswire: Don't depend on NEW_LEDS

The ExpressWire library does not depend on NEW_LEDS and selecting it
from a subsystem other than LEDs may cause Kconfig warnings:

WARNING: unmet direct dependencies detected for LEDS_EXPRESSWIRE
  Depends on [n]: NEW_LEDS [=n] && GPIOLIB [=y]
  Selected by [y]:
  - BACKLIGHT_KTD2801 [=y] && HAS_IOMEM [=y] && BACKLIGHT_CLASS_DEVICE [=y]

Move it out of the "if NEW_LEDS" block to allow selection from other
subsystems (in particular backlight) without raising this warning.
Reported-by: Arnd Bergmann <arnd@arndb.de>
Closes: https://lore.kernel.org/20240212111819.936815-1-arnd@kernel.orgReported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202402161410.IG9I4odj-lkp@intel.com/Suggested-by: Daniel Thompson <daniel.thompson@linaro.org>
Fixes: 25ae5f5f4168 ("leds: Introduce ExpressWire library")
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Duje Mihanović <duje.mihanovic@skole.hr>
Link: https://lore.kernel.org/r/20240216-expresswire-deps-v2-2-8be59c4a75f5@skole.hrSigned-off-by: Lee Jones <lee@kernel.org>

drivers/leds/Kconfig

@@ -6,6 +6,12 @@ config LEDS_GPIO_REGISTER
 	  As this function is used by arch code it must not be compiled as a
 	  module.
 
+# This library does not depend on NEW_LEDS and must be independent so it can be
+# selected from other subsystems (specifically backlight).
+config LEDS_EXPRESSWIRE
+	bool
+	depends on GPIOLIB
+
 menuconfig NEW_LEDS
 	bool "LED Support"
 	help