i2c: designware: Use `-y` to build multi-object modules

Since commit 4f827280 ("Documentation: update kbuild loadable modules
goals & examples") `-objs` is fitted for building host programs, lets
change DW I2C core, platform and PCI driver kbuild directives to using
`-y`, which more straightforward for device drivers. By doing so we can
discard the ifeq construction in favor to the more natural and less bulky
`<module>-$(CONFIG_X) += x.o`
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

drivers/i2c/busses/Makefile

@@ -48,17 +48,15 @@ obj-$(CONFIG_I2C_CADENCE)	+= i2c-cadence.o
 obj-$(CONFIG_I2C_CBUS_GPIO)	+= i2c-cbus-gpio.o
 obj-$(CONFIG_I2C_CPM)		+= i2c-cpm.o
 obj-$(CONFIG_I2C_DAVINCI)	+= i2c-davinci.o
-obj-$(CONFIG_I2C_DESIGNWARE_CORE)	+= i2c-designware-core.o
-i2c-designware-core-objs := i2c-designware-common.o
-i2c-designware-core-objs += i2c-designware-master.o
-ifeq ($(CONFIG_I2C_DESIGNWARE_SLAVE),y)
-i2c-designware-core-objs += i2c-designware-slave.o
-endif
-obj-$(CONFIG_I2C_DESIGNWARE_PLATFORM)	+= i2c-designware-platform.o
-i2c-designware-platform-objs := i2c-designware-platdrv.o
+obj-$(CONFIG_I2C_DESIGNWARE_CORE)			+= i2c-designware-core.o
+i2c-designware-core-y					:= i2c-designware-common.o
+i2c-designware-core-y					+= i2c-designware-master.o
+i2c-designware-core-$(CONFIG_I2C_DESIGNWARE_SLAVE) 	+= i2c-designware-slave.o
+obj-$(CONFIG_I2C_DESIGNWARE_PLATFORM)			+= i2c-designware-platform.o
+i2c-designware-platform-y 				:= i2c-designware-platdrv.o
 i2c-designware-platform-$(CONFIG_I2C_DESIGNWARE_BAYTRAIL) += i2c-designware-baytrail.o
-obj-$(CONFIG_I2C_DESIGNWARE_PCI)	+= i2c-designware-pci.o
-i2c-designware-pci-objs := i2c-designware-pcidrv.o
+obj-$(CONFIG_I2C_DESIGNWARE_PCI)			+= i2c-designware-pci.o
+i2c-designware-pci-y					:= i2c-designware-pcidrv.o
 obj-$(CONFIG_I2C_DIGICOLOR)	+= i2c-digicolor.o
 obj-$(CONFIG_I2C_EFM32)		+= i2c-efm32.o
 obj-$(CONFIG_I2C_EG20T)		+= i2c-eg20t.o