Revert seccomp tests that allow it to be used on non-x86 architectures

Unfortunately it turns out that libseccomp 2.2 still does not work
correctly on non-x86 architectures; return to the previous configure
setup of insisting on libseccomp 2.1 or better and i386/x86_64 and
disabling seccomp support in all other situations.

This reverts the two commits:
 * "seccomp: libseccomp version varying according to arch"
   (commit 896848f)
 * "seccomp: update libseccomp version and remove arch restriction"
   (commit 8e27fc2)

Signed-off-by: Peter Maydell <[email protected]>
Message-id: [email protected]

configure

@@ -1848,19 +1848,14 @@ fi
 # libseccomp check
 
 if test "$seccomp" != "no" ; then
-    if $pkg_config --atleast-version=2.2.0 libseccomp ||
-        (test "$cpu" = "i386" || test "$cpu" = "x86_64" &&
-        $pkg_config --atleast-version=2.1.1 libseccomp); then
+    if test "$cpu" = "i386" || test "$cpu" = "x86_64" &&
+        $pkg_config --atleast-version=2.1.1 libseccomp; then
         libs_softmmu="$libs_softmmu `$pkg_config --libs libseccomp`"
         QEMU_CFLAGS="$QEMU_CFLAGS `$pkg_config --cflags libseccomp`"
 	seccomp="yes"
     else
 	if test "$seccomp" = "yes"; then
-        if test "$cpu" = "i386" || test "$cpu" = "x86_64"; then
             feature_not_found "libseccomp" "Install libseccomp devel >= 2.1.1"
-        else
-            feature_not_found "libseccomp" "Install libseccomp devel >= 2.2.0"
-        fi
 	fi
 	seccomp="no"
     fi