compat: backport print_hex_dump_debug()

This backports print_hex_dump_debug() from commit
7a555613, which itself required a definition from
commit 07613b0b.

mcgrof@frijol ~/linux-stable (git::master)$ git describe --contains 7a555613
v3.9-rc1~128^2~135

mcgrof@frijol ~/linux-stable (git::master)$ git describe --contains 07613b0b
v3.2-rc1~184^2~6

commit 7a555613eb77c69eb6e48b61bc5f72dd42fa1780
Author: Vladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Date:   Wed Dec 5 16:48:27 2012 -0500

    dynamic_debug: dynamic hex dump

    Introduce print_hex_dump_debug() that can be dynamically controlled, similar to
    pr_debug.

    Also, make print_hex_dump_bytes() dynamically controlled

    Implement only 'p' flag (_DPRINTK_FLAGS_PRINT) to keep it simple since hex dump prints
    multiple lines and long prefix would impact readability.
    To provide line/file etc. information, use pr_debug or similar
    before/after print_hex_dump_debug()

    Signed-off-by: Vladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
    Signed-off-by: Jason Baron <jbaron@redhat.com>
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 07613b0b5ef8570033aa806d1731dce599862223
Author: Jason Baron <jbaron@redhat.com>
Date:   Tue Oct 4 14:13:15 2011 -0700

    dynamic_debug: consolidate repetitive struct _ddebug descriptor definitions

    Replace the repetitive struct _ddebug descriptor definitions with a new
    DECLARE_DYNAMIC_DEBUG_META_DATA(name, fmt) macro.

    [akpm@linux-foundation.org: s/DECLARE/DEFINE/]
    Signed-off-by: Jason Baron <jbaron@redhat.com>
    Cc: Arnd Bergmann <arnd@arndb.de>
    Signed-off-by: Andrew Morton <akpm@google.com>
    Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Signed-off-by: Luis R. Rodriguez <mcgrof@do-not-panic.com>