Convert Makefiles from COBJS-${} to COBJS-$()

Match style we use almost everywhere else

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
diff --git a/board/freescale/common/Makefile b/board/freescale/common/Makefile
index 620eb16..df289aa 100644
--- a/board/freescale/common/Makefile
+++ b/board/freescale/common/Makefile
@@ -29,18 +29,18 @@
 
 LIB	= $(obj)lib$(VENDOR).a
 
-COBJS-${CONFIG_FSL_CADMUS}	+= cadmus.o
-COBJS-${CONFIG_FSL_VIA}		+= cds_via.o
-COBJS-${CONFIG_FSL_DIU_FB}	+= fsl_diu_fb.o fsl_logo_bmp.o
-COBJS-${CONFIG_FSL_PIXIS}	+= pixis.o
-COBJS-${CONFIG_FSL_NGPIXIS}	+= ngpixis.o
-COBJS-${CONFIG_PQ_MDS_PIB}	+= pq-mds-pib.o
-COBJS-${CONFIG_ID_EEPROM}	+= sys_eeprom.o
-COBJS-${CONFIG_FSL_SGMII_RISER}	+= sgmii_riser.o
+COBJS-$(CONFIG_FSL_CADMUS)	+= cadmus.o
+COBJS-$(CONFIG_FSL_VIA)		+= cds_via.o
+COBJS-$(CONFIG_FSL_DIU_FB)	+= fsl_diu_fb.o fsl_logo_bmp.o
+COBJS-$(CONFIG_FSL_PIXIS)	+= pixis.o
+COBJS-$(CONFIG_FSL_NGPIXIS)	+= ngpixis.o
+COBJS-$(CONFIG_PQ_MDS_PIB)	+= pq-mds-pib.o
+COBJS-$(CONFIG_ID_EEPROM)	+= sys_eeprom.o
+COBJS-$(CONFIG_FSL_SGMII_RISER)	+= sgmii_riser.o
 
-COBJS-${CONFIG_MPC8541CDS}	+= cds_pci_ft.o
-COBJS-${CONFIG_MPC8548CDS}	+= cds_pci_ft.o
-COBJS-${CONFIG_MPC8555CDS}	+= cds_pci_ft.o
+COBJS-$(CONFIG_MPC8541CDS)	+= cds_pci_ft.o
+COBJS-$(CONFIG_MPC8548CDS)	+= cds_pci_ft.o
+COBJS-$(CONFIG_MPC8555CDS)	+= cds_pci_ft.o
 
 
 SRCS	:= $(SOBJS:.o=.S) $(COBJS-y:.o=.c)