[PATCH] powerpc: add setmaskedbits macros

[Paul Mackerras]

Timur Tabi writes:

> This patch adds the setmaskedbits_xxx() macros, which are used to set a
> multiple-bit bit pattern in a register.  The macros include a mask, which
> zeros the respective bits before applying the value via a bitwise-OR.
> There are big-endian and little-endian versions for 8, 16, 32, and 64 bits.

Why do we want these?  (Don't tell me, put it in the commit log. :)

Paul.