pwm: renesas-tpu: Enable driver compilation with COMPILE_TEST

This helps increasing build testing coverage.

Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: linux-pwm@vger.kernel.org
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

drivers/pwm/Kconfig

@@ -139,7 +139,7 @@ config PWM_PXA
 
 config PWM_RENESAS_TPU
 	tristate "Renesas TPU PWM support"
-	depends on ARCH_SHMOBILE
+	depends on ARCH_SHMOBILE || COMPILE_TEST
 	help
 	  This driver exposes the Timer Pulse Unit (TPU) PWM controller found
 	  in Renesas chips through the PWM API.