gpio: Add proper dependency on ZYNQMP_FIRMWARE

ZYNQMP_FIRMWARE can be disabled and driver depends on it that's why record
this dependency via Kconfig.

Signed-off-by: Michal Simek <michal.simek@amd.com>
Link: https://lore.kernel.org/r/c3ca38fbb2f4e6948a5ef95b369015de96259709.1717685091.git.michal.simek@amd.com
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 2c0e244..fcca694 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -639,7 +639,7 @@
 
 config ZYNQMP_GPIO_MODEPIN
 	bool "ZynqMP gpio modepin"
-	depends on DM_GPIO
+	depends on DM_GPIO && ZYNQMP_FIRMWARE
 	help
 	  This config enables the ZynqMP gpio modepin driver. ZynqMP modepin
 	  driver will set and get the status of PS_MODE pins. These modepins