pwm: jz4740: Improve compile coverage by allowing to enable on !MIPS

There are no mips specific constructs in this driver and it compiles
just fine with ARCH=arm.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

drivers/pwm/Kconfig

@@ -272,7 +272,7 @@ config PWM_IQS620A
 
 config PWM_JZ4740
 	tristate "Ingenic JZ47xx PWM support"
-	depends on MIPS
+	depends on MIPS || COMPILE_TEST
 	depends on COMMON_CLK
 	select MFD_SYSCON
 	help