misc: mark spear13xx-pcie-gadget as broken

This driver was merged in 2.6.38 but never actually compiled because
it depends on the <mach/pcie.h> header that has not made it into the
kernel. Starting with Linux-3.10, this results in "allyesconfig"
build errors, since spear13xx can now be enabled with the default
"multiplatform" platform on ARM. Let's mark it as broken for now.
If it doesn't get fixed, we can drop it completely.

Cc: Pratyush Anand <pratyush.anand@st.com>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Cc: Viresh Kumar <viresh.kumar@st.com>
Cc: Shiraz Hashim <shiraz.hashim@st.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>