powerpc/64: set DSCR default initially from SPR

[Michael Ellerman]

On Tue, 2017-10-24 at 11:44:44 UTC, Nicholas Piggin wrote:
> Take the DSCR value set by firmware as the dscr_default value,
> rather than zero.
> 
> POWER9 recommends DSCR default to a non-zero value.
> 
> From: Nicholas Piggin <npiggin at gmail.com>

Applied to powerpc next, thanks.

https://git.kernel.org/powerpc/c/1696d0fb7fcd18160c9cc92a3f2b2d

cheers