dmaengine: dw: Replace 'objs' by 'y'

`-objs` is fitted for building host programs, change to `-y`,
more straightforward for device drivers.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20200526182416.52805-2-andriy.shevchenko@linux.intel.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

drivers/dma/dw/Makefile

 # SPDX-License-Identifier: GPL-2.0
 obj-$(CONFIG_DW_DMAC_CORE)	+= dw_dmac_core.o
-dw_dmac_core-objs	:= core.o dw.o idma32.o
+dw_dmac_core-y			:= core.o dw.o idma32.o
 dw_dmac_core-$(CONFIG_ACPI)	+= acpi.o
 
 obj-$(CONFIG_DW_DMAC)		+= dw_dmac.o
@@ -8,4 +8,4 @@ dw_dmac-y			:= platform.o
 dw_dmac-$(CONFIG_OF)		+= of.o
 
 obj-$(CONFIG_DW_DMAC_PCI)	+= dw_dmac_pci.o
-dw_dmac_pci-objs	:= pci.o
+dw_dmac_pci-y			:= pci.o