boards.cfg: update highbank maintainer email

My Calxeda email is gone, so update my email address.
Signed-off-by: NRob Herring <robh@kernel.org>

boards.cfg

@@ -295,7 +295,7 @@ Active  arm         armv7          exynos      samsung         smdkv310
 Active  arm         armv7          exynos      samsung         trats               trats                                 -                                                                                                                                 Lukasz Majewski <l.majewski@samsung.com>
 Active  arm         armv7          exynos      samsung         trats2              trats2                                -                                                                                                                                 Piotr Wilczek <p.wilczek@samsung.com>
 Active  arm         armv7          exynos      samsung         universal_c210      s5pc210_universal                     -                                                                                                                                 Przemyslaw Marczak <p.marczak@samsung.com>
-Active  arm         armv7          highbank    -               highbank            highbank                              -                                                                                                                                 Rob Herring <rob.herring@calxeda.com>
+Active  arm         armv7          highbank    -               highbank            highbank                              -                                                                                                                                 Rob Herring <robh@kernel.org>
 Active  arm         armv7          keystone    ti              k2hk_evm            k2hk_evm                              -                                                                                                                                 Vitaly Andrianov <vitalya@ti.com>
 Active  arm         armv7          mx5         denx            m53evk              m53evk                                m53evk:IMX_CONFIG=board/denx/m53evk/imximage.cfg                                                                                  Marek Vasut <marek.vasut@gmail.com>
 Active  arm         armv7          mx5         esg             ima3-mx53           ima3-mx53                             ima3-mx53:IMX_CONFIG=board/esg/ima3-mx53/imximage.cfg                                                                             -