staging: hikey9xx: add build for the Kirin 970 PHY driver

Add the needed bits in order to build the Kirin 970 PHY
driver.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/60aae73e91348430e940638cf9668a0a63a85c1c.1600338981.git.mchehab+huawei@kernel.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/hikey9xx/Kconfig

 # SPDX-License-Identifier: GPL-2.0
 
+# to be placed at drivers/phy
+config PHY_HI3670_USB
+	tristate "hi3670 USB PHY support"
+	depends on (ARCH_HISI && ARM64) || COMPILE_TEST
+	select GENERIC_PHY
+	select MFD_SYSCON
+	help
+	  Enable this to support the HISILICON HI3670 USB PHY.
+
+	  To compile this driver as a module, choose M here.
+
 # to be placed at drivers/spmi
 config SPMI_HISI3670
 	tristate "Hisilicon 3670 SPMI Controller"

drivers/staging/hikey9xx/Makefile

 # SPDX-License-Identifier: GPL-2.0
 
+obj-$(CONFIG_PHY_HI3670_USB)		+= phy-hi3670-usb3.o
+
 obj-$(CONFIG_SPMI_HISI3670)		+= hisi-spmi-controller.o
 obj-$(CONFIG_MFD_HI6421_SPMI)		+= hi6421-spmi-pmic.o
 obj-$(CONFIG_REGULATOR_HI6421V600)	+= hi6421v600-regulator.o