scripts: Add ppc64le support for checkstack.pl

[Michael Ellerman]

On Tue, 2017-11-28 at 19:29:34 UTC, Breno Leitao wrote:
> 64-bit ELF v2 ABI specification for POWER describes, on section "General
> Stack Frame Requirements", that the stack should use the following
> instructions when compiled with backchain:
> 
>   mflr r0
>   std  r0, 16(r1)
>   stdu r1, -XX(r1)
> 
> Where XX is the frame size for that function, and this is the value
> checkstack.pl will find the stack size for each function.
> 
> This patch also simplifies the entire Powerpc section, since just two
> type of instructions are used, 'stdu' for 64 bits and 'stwu' for 32 bits
> platform.
> 
> Signed-off-by: Breno Leitao <leitao at debian.org>

Applied to powerpc next, thanks.

https://git.kernel.org/powerpc/c/8449a4cb69ab6fbb873d653a82787a

cheers