kvm tools: Move disk image related code under disk directory

This patch removes disk-image.c and qcow.c under disk directory.

Signed-off-by: Asias He <asias.hejun@gmail.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>

Makefile

@@ -15,7 +15,7 @@ TAGS = ctags
 OBJS	+= 8250-serial.o
 OBJS	+= cpuid.o
 OBJS	+= read-write.o
-OBJS	+= disk-image.o
+OBJS	+= disk/disk-image.o
 OBJS	+= interrupt.o
 OBJS	+= ioport.o
 OBJS	+= kvm.o
@@ -37,7 +37,7 @@ OBJS    += util/strbuf.o
 OBJS    += kvm-help.o
 OBJS    += kvm-cmd.o
 OBJS    += kvm-run.o
-OBJS    += qcow.o
+OBJS    += disk/qcow.o
 OBJS    += mptable.o
 OBJS    += threadpool.o
 OBJS    += irq.o