git: mailrc: Update e-mail address

Signed-off-by: Lukasz Majewski <lukma@denx.de>

doc/git-mailrc

@@ -31,7 +31,7 @@ alias jhersh         Joe Hershberger <joe.hershberger@ni.com>
 alias jwrdegoede     Hans de Goede <hdegoede@redhat.com>
 alias kimphill       Kim Phillips <kim.phillips@freescale.com>
 alias luka           Luka Perkov <luka.perkov@sartura.hr>
-alias lukma          Lukasz Majewski <l.majewski@samsung.com>
+alias lukma          Lukasz Majewski <l.majewski@denx.de>
 alias macpaul        Macpaul Lin <macpaul@andestech.com>
 alias marex          Marek Vasut <marex@denx.de>
 alias masahiro       Masahiro Yamada <yamada.masahiro@socionext.com>