build: fix race when creating the cpu_map.xml symlink

In some circumstances where the build tree differs from the source,
libvirt's compile will try to create the symlink for cpu_map.xml before
creating the directory $(abs_builddir)/cpu:

'src/cpu/cpu_map.xml': No such file or directory'

Do not create the symlink, it is no longer needed after
commit e562e82f
    Load CPU map from builddir when run uninstalled
Signed-off-by: NAmy Fong <amy.fong@windriver.com>
Signed-off-by: NJán Tomko <jtomko@redhat.com>
(cherry picked from commit 237ffd1b)

src/Makefile.am

@@ -1035,10 +1035,6 @@ libvirt_la_BUILT_LIBADD += libvirt_cpu.la
 libvirt_cpu_la_CFLAGS = \
 		-I$(srcdir)/conf $(AM_CFLAGS)
 libvirt_cpu_la_SOURCES = $(CPU_SOURCES)
-libvirt_cpu_la_DEPENDENCIES = $(abs_builddir)/cpu/cpu_map.xml
-
-$(abs_builddir)/cpu/cpu_map.xml:
-	$(AM_V_GEN)ln -s $(abs_srcdir)/cpu/cpu_map.xml $@
 
 if WITH_VMX
 noinst_LTLIBRARIES += libvirt_vmx.la