gpio/hsdk: Depend on DM_GPIO instead of simple DM

This driver really is DM GPIO one and so we need to have a correct
dependency, because DM alone doesn't provide required for CMD_GPIO
call and we're seeing build failures like this:
---------------------->8---------------------
cmd/built-in.o: In function 'do_gpio':
.../cmd/gpio.c:188: undefined reference to 'gpio_request'
...
---------------------->8---------------------

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Cc: Eugeniy Paltsev <paltsev@synopsys.com>
Cc: Simon Glass <sjg@chromium.org>
Reviewed-by: Simon Glass <sjg@chromium.org>

drivers/gpio/Kconfig

@@ -82,7 +82,7 @@ config IMX_RGPIO2P
 
 config HSDK_CREG_GPIO
 	bool "HSDK CREG GPIO griver"
-	depends on DM
+	depends on DM_GPIO
 	default n
 	help
 	  This driver supports CREG GPIOs on Synopsys HSDK SOC.