net: dsa: qca8k: fix LEDS_CLASS dependency

With LEDS_CLASS=m, a built-in qca8k driver fails to link:

arm-linux-gnueabi-ld: drivers/net/dsa/qca/qca8k-leds.o: in function `qca8k_setup_led_ctrl':
qca8k-leds.c:(.text+0x1ea): undefined reference to `devm_led_classdev_register_ext'

Change the dependency to avoid the broken configuration.

Fixes: 1e264f9d2918 ("net: dsa: qca8k: add LEDs basic support")
Signed-off-by: Arnd Bergmann <[e-mail]>
Reviewed-by: Christian Marangi <[e-mail]>
Reviewed-by: Andrew Lunn <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Jakub Kicinski <[e-mail]>

drivers/net/dsa/qca/Kconfig

···
 config NET_DSA_QCA8K_LEDS_SUPPORT
 	bool "Qualcomm Atheros QCA8K Ethernet switch family LEDs support"
 	depends on NET_DSA_QCA8K
-	depends on LEDS_CLASS
+	depends on LEDS_CLASS=y || LEDS_CLASS=NET_DSA_QCA8K
 	help
 	  This enabled support for LEDs present on the Qualcomm Atheros
 	  QCA8K Ethernet switch chips.