reset: berlin: add driver Kconfig option

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

Cc: Antoine Tenart <antoine.tenart@free-electrons.com>
Cc: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
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 e3fc337..34c0b23 100644
--- a/drivers/reset/Makefile
+++ b/drivers/reset/Makefile
@@ -1,7 +1,6 @@
 obj-y += core.o
 obj-$(CONFIG_ARCH_LPC18XX) += reset-lpc18xx.o
 obj-$(CONFIG_ARCH_SOCFPGA) += reset-socfpga.o
-obj-$(CONFIG_ARCH_BERLIN) += reset-berlin.o
 obj-$(CONFIG_MACH_PISTACHIO) += reset-pistachio.o
 obj-$(CONFIG_ARCH_MESON) += reset-meson.o
 obj-$(CONFIG_ARCH_STM32) += reset-stm32.o
@@ -10,6 +9,7 @@
 obj-$(CONFIG_ARCH_HISI) += hisilicon/
 obj-$(CONFIG_ARCH_ZYNQ) += reset-zynq.o
 obj-$(CONFIG_RESET_ATH79) += reset-ath79.o
+obj-$(CONFIG_RESET_BERLIN) += reset-berlin.o
 obj-$(CONFIG_RESET_OXNAS) += reset-oxnas.o
 obj-$(CONFIG_TI_SYSCON_RESET) += reset-ti-syscon.o
 obj-$(CONFIG_RESET_UNIPHIER) += reset-uniphier.o