ref-manual: Added the PACKAGE_ARCHS variable.

(From yocto-docs rev: 436758c094db7fc51aa14ee7870d7dac678b416e)

Signed-off-by: Scott Rifenbark <scott.m.rifenbark@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

documentation/ref-manual/ref-variables.xml

@@ -5453,6 +5453,24 @@ recipes-graphics/xorg-font/font-alias_1.0.3.bb:PR = "${INC_PR}.3"
             </glossdef>
         </glossentry>
 
+        <glossentry id='var-PACKAGE_ARCHS'><glossterm>PACKAGE_ARCHS</glossterm>
+            <glossdef>
+                <para>
+                    Specifies a list of architectures compatible with
+                    the target machine.
+                    Separate the entries using spaces and list them in order
+                    of priority.
+                    This variable is set automatically and should not
+                    normally be hand-edited.
+                    The default value for
+                    <filename>PACKAGE_ARCHS</filename> is "all any noarch
+                    ${PACKAGE_EXTRA_ARCHS} ${MACHINE_ARCH}"
+                </para>
+            </glossdef>
+        </glossentry>
+
+
+
         <glossentry id='var-PACKAGE_BEFORE_PN'><glossterm>PACKAGE_BEFORE_PN</glossterm>
             <glossdef>
                 <para>Enables easily adding packages to