leds: flash: leds-qcom-flash: Declare the driver as a module

Explain in Kconfig that the driver can be compiled as a module.
Signed-off-by: Fenglin Wu <quic_fenglinw@quicinc.com>
Link: https://lore.kernel.org/r/20230725-leds-qcom-flash-driver-tiny-fixes-v2-1-0f5cbce5fed0@quicinc.comSigned-off-by: Lee Jones <lee@kernel.org>

drivers/leds/flash/Kconfig

@@ -89,6 +89,8 @@ config LEDS_QCOM_FLASH
 	  the total LED current will be split symmetrically on each channel and
 	  they will be enabled/disabled at the same time.
 
+	  This driver can be built as a module, it will be called "leds-qcom-flash".
+
 config LEDS_RT4505
 	tristate "LED support for RT4505 flashlight controller"
 	depends on I2C && OF