staging: nvec: do not depend on MACH_PAZ00

With the removal of board files on the tegra arch, drivers can now only
be instantiated via device tree. Consequently, all MACH_<board> config
variables are removed. As a temporary solution always enable building
for the (up to now) only supported paz00 board until nvec is full ported
to device tree.

Signed-off-by: Marc Dietrich <marvin24@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>