reset: ath79: add driver Kconfig option

Visible only if COMPILE_TEST is enabled, this allows to include the
driver in build tests.

Acked-by: Aban Bedel <albeu@free.fr>
Reviewed-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile
index 9b45dcf..e3fc337 100644
--- a/drivers/reset/Makefile
+++ b/drivers/reset/Makefile
@@ -9,7 +9,7 @@
 obj-$(CONFIG_ARCH_STI) += sti/
 obj-$(CONFIG_ARCH_HISI) += hisilicon/
 obj-$(CONFIG_ARCH_ZYNQ) += reset-zynq.o
-obj-$(CONFIG_ATH79) += reset-ath79.o
+obj-$(CONFIG_RESET_ATH79) += reset-ath79.o
 obj-$(CONFIG_RESET_OXNAS) += reset-oxnas.o
 obj-$(CONFIG_TI_SYSCON_RESET) += reset-ti-syscon.o
 obj-$(CONFIG_RESET_UNIPHIER) += reset-uniphier.o