imx: refactor imx_get_mac_from_fuse

Move imx_get_mac_from_fuse to a new mac.c for i.MX6/7.
Since fuse regs structure are different for i.MX6/7, use mac
address offset in code and define a new local struture
imx_mac_fuse.

Also sort the config order.

Signed-off-by: Peng Fan <peng.fan@nxp.com>
Cc: Stefano Babic <sbabic@denx.de>
Cc: Fabio Estevam <fabio.estevam@nxp.com>
Reviewed-by: Stefano Babic <sbabic@denx.de>
diff --git a/arch/arm/mach-imx/Makefile b/arch/arm/mach-imx/Makefile
index 63db0e1..714b858 100644
--- a/arch/arm/mach-imx/Makefile
+++ b/arch/arm/mach-imx/Makefile
@@ -25,12 +25,13 @@
 endif
 ifeq ($(SOC),$(filter $(SOC),mx6 mx7))
 obj-y 	+= cache.o init.o
-obj-$(CONFIG_SATA) += sata.o
+obj-$(CONFIG_FEC_MXC) += mac.o
 obj-$(CONFIG_IMX_VIDEO_SKIP) += video.o
 obj-$(CONFIG_IMX_RDC) += rdc-sema.o
 ifneq ($(CONFIG_SPL_BUILD),y)
 obj-$(CONFIG_IMX_BOOTAUX) += imx_bootaux.o
 endif
+obj-$(CONFIG_SATA) += sata.o
 obj-$(CONFIG_SECURE_BOOT)    += hab.o
 obj-$(CONFIG_SYSCOUNTER_TIMER) += syscounter.o
 endif