powerpc/Makefile: Use cflags-y/aflags-y for setting endian options

[Michael Ellerman]

On Tue, 2016-09-08 at 12:43:46 UTC, Michael Ellerman wrote:
> When we introduced the little endian support, we added the endian flags
> to CC directly using override. I don't know the history of why we did
> that, I suspect no one does.
> 
> Although this mostly works, it has one bug, which is that CROSS32CC
> doesn't get -mbig-endian. That means when the compiler is little endian
> by default and the user is building big endian, vdso32 is incorrectly
> compiled as little endian and the kernel fails to build.
> 
> Instead we can add the endian flags to cflags-y/aflags-y, and then
> append those to KBUILD_CFLAGS/KBUILD_AFLAGS.
> 
> This has the advantage of being 1) less ugly, 2) the documented way of
> adding flags in the arch Makefile and 3) it fixes building vdso32 with a
> LE toolchain.
> 
> Signed-off-by: Michael Ellerman <mpe at ellerman.id.au>

Applied to powerpc fixes.

https://git.kernel.org/powerpc/c/164af597ce945751e2dcd53d0a

cheers