Update U-Boot's version of scripts/get_maintainer.pl to sync it up with
the latest changes to the Linux kernel's version of the same script.

The last sync was with Linux kernel version v5.13-rc6. The commits to
the kernel's get_maintainer.pl since then (starting with the most
recent) are:
        11fb48961e52 get_maintainer: Honor mailmap for in file emails
        26d98e9f78da get_maintainer: don't remind about no git repo when --nogit is used

Signed-off-by: Tom Rini <trini@konsulko.com>