drm/amd/display: use ARCH_HAS_KERNEL_FPU_SUPPORT

drm/amd/display: use ARCH_HAS_KERNEL_FPU_SUPPORT

Now that all previously-supported architectures select
ARCH_HAS_KERNEL_FPU_SUPPORT, this code can depend on that symbol instead
of the existing list of architectures.  It can also take advantage of the
common kernel-mode FPU API and method of adjusting CFLAGS.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Samuel Holland <[email protected]>
Acked-by: Alex Deucher <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Acked-by: Christian König <[email protected]>
Cc: Borislav Petkov (AMD) <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: Huacai Chen <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Cc: Masahiro Yamada <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Nathan Chancellor <[email protected]>
Cc: Nicolas Schier <[email protected]>
Cc: Palmer Dabbelt <[email protected]>
Cc: Russell King <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: WANG Xuerui <[email protected]>
Cc: Will Deacon <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>