[PATCH, binutils/ARM] Remove legacy basepri_mask MRS/MSR special reg

[Nick Clifton]

Hi Thomas,

> 2016-09-12  Thomas Preud'homme  <thomas.preudhomme@arm.com>
> 
>         * config/tc-arm.c (v7m_psrs): Remove BASEPRI_MASK MRS/MSR special
>         register and redundant basepri_max.

Approved - please apply.

Cheers
  Nick