leds: qcom-lpg: add missing PWM dependency

The Qualcomm LPG driver fails to probe unless PWM support is enabled so
add the missing Kconfig dependency.

Fixes: 24e2d05d ("leds: Add driver for Qualcomm LPG")
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Signed-off-by: Pavel Machek <pavel@ucw.cz>

drivers/leds/rgb/Kconfig

@@ -15,6 +15,7 @@ config LEDS_PWM_MULTICOLOR
 config LEDS_QCOM_LPG
 	tristate "LED support for Qualcomm LPG"
 	depends on OF
+	depends on PWM
 	depends on SPMI
 	help
 	  This option enables support for the Light Pulse Generator found in a