linux-yocto: add blktrace feature

linux-yocto: add blktrace feature

Updating the 3.0 kernel to enable blktrace to match our previous
functionality. This is done by the following meta branch commit:

[
    meta: add blktrace feature

    Add a 'blktrace feature' that turns on kernel support for blktrace, a
    block I/O tracing tool.  Added to 'standard' alongside similar tracing
    tool config.

    (From OE-Core rev: 21654cbf766f9c319b2fc8a08f0060c60ef005eb)

Signed-off-by: Tom Zanussi <tom.zanussi@intel.com>
]

Signed-off-by: Bruce Ashfield <bruce.ashfield@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>