USB: atm: ueagle-atm.c: fix SPDX tag to be BSD2

USB: atm: ueagle-atm.c: fix SPDX tag to be BSD2

Thomas rightly points out that I got the BSD clause count wrong for this
driver, it should be 2, not 3 based on the text in the license here, so
fix that up.

He also raises the question that the license text points to a v2 only
license, yet the text in the header says "or later".  Given that the
text in the header says "or later" and all of the other USB atm drivers
are licensed in that way, I am going to leave the string as-is for that
mark.

Reported-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Matthieu CASTET <castet.matthieu@free.fr>
Cc: Stanislaw Gruszka <stf_xl@wp.pl>
Cc: Damien Bergamini <damien.bergamini@free.fr>
Cc: Duncan Sands <duncan.sands@free.fr>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>