nios2: convert altera sysid to driver model

Convert altera sysid to driver model with misc uclass.

Signed-off-by: Thomas Chou <thomas@wytron.com.tw>
Acked-by: Chin Liang See <clsee@altera.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/nios2/cpu/Makefile b/arch/nios2/cpu/Makefile
index 3fe7847..185ca3c 100644
--- a/arch/nios2/cpu/Makefile
+++ b/arch/nios2/cpu/Makefile
@@ -7,5 +7,5 @@
 
 extra-y	= start.o
 obj-y	= exceptions.o
-obj-y	+= cpu.o interrupts.o sysid.o traps.o
+obj-y	+= cpu.o interrupts.o traps.o
 obj-y	+= fdt.o