MSCC: add support for Luton SoCs

As the Ocelots SoCs, this family of SoCs are found in the Microsemi
Switches solution.

Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>
diff --git a/arch/mips/mach-mscc/Makefile b/arch/mips/mach-mscc/Makefile
index d14ec33..6c60f26 100644
--- a/arch/mips/mach-mscc/Makefile
+++ b/arch/mips/mach-mscc/Makefile
@@ -3,3 +3,4 @@
 CFLAGS_cpu.o += -finline-limit=64000
 
 obj-y += cpu.o dram.o reset.o lowlevel_init.o
+obj-$(CONFIG_SOC_LUTON) += lowlevel_init_luton.o