kconfig: fix xconfig on fedora 2 & 3 (x86_64)

From: Than Ngo <than@redhat.com>
qt as installed on fedora core (2 and 3) does not work with vanilla
kernel. The linker fails to locate the qt lib:

Actual Results:  # make xconfig
  HOSTLD  scripts/kconfig/qconf
  /usr/bin/ld: cannot find -lqt
  collect2: ld returned 1 exit status

Than Ngo has provided following fix for the bug.

Cc: Than Ngo <than@redhat.com>
Acked-by: Dave Jones <davej@redhat.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>