backports: backport dma-buf debugfs support

backports: backport dma-buf debugfs support

Commit 5a753a4 on next-20130410 extended the
dma-buf implementation to add debugfs support.
We backport support for this by adding its own
subsys_init() call as a helper to the backport
module (still called compat) respective subsys_init()
call, backport_init(). For kernels where this is
already supported this is a no-op.

This didn't make it to v3.9 but I see Linus has
already merged this as part of the merge window
what will be v3.10.

This also refreshes patches for next-20130410 and
I supply the refresh as part of this same patch
given that the only patch refreshed was the one
modifyin the drivers/base/dma-buf.c.

commit 5a753a49fb7e17fa83ea9cf39c7b1a902363d828
Author: Sumit Semwal <sumit.semwal@linaro.org>
Date:   Thu Apr 4 11:44:37 2013 +0530

    dma-buf: Add debugfs support

    Add debugfs support to make it easier to print debug information
    about the dma-buf buffers.

    Cc: Dave Airlie <airlied@redhat.com>
     [minor fixes on init and warning fix]
    Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
$ ckmake --allyesconfig

1   2.6.24              [  OK  ]
2   2.6.25              [  OK  ]
3   2.6.26              [  OK  ]
4   2.6.27              [  OK  ]
5   2.6.28              [  OK  ]
6   2.6.29              [  OK  ]
7   2.6.30              [  OK  ]
8   2.6.31              [  OK  ]
9   2.6.32              [  OK  ]
10  2.6.33              [  OK  ]
11  2.6.34              [  OK  ]
12  2.6.35              [  OK  ]
13  2.6.36              [  OK  ]
14  2.6.37              [  OK  ]
15  2.6.38              [  OK  ]
16  2.6.39              [  OK  ]
17  3.0.76              [  OK  ]
18  3.1.10              [  OK  ]
19  3.2.44              [  OK  ]
20  3.3.8               [  OK  ]
21  3.4.43              [  OK  ]
22  3.5.7               [  OK  ]
23  3.6.11              [  OK  ]
24  3.7.10              [  OK  ]
25  3.8.11              [  OK  ]
26  3.9.0               [  OK  ]

real    30m10.328s
user    797m1.841s
sys     125m15.978s

Signed-off-by: Luis R. Rodriguez <mcgrof@do-not-panic.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>