readme.md: Update csky and m68k

CSKY support was merged in LLVM 12. m68k support was merged in LLVM 13.
As far as I am aware, CSKY has seen no testing and m68k is still broken.

Signed-off-by: Nathan Chancellor <nathan@kernel.org>

Author: nathanchance

readme.md

@@ -52,15 +52,15 @@ best-effort basis:
 The following architectures are targetable from both LLVM and the Linux kernel
 but are untested or currently broken:
 * arc
+* csky
+* m68k
 * sparc
 
 The following architectures are targetable from the Linux kernel but not LLVM:
 * alpha
 * c6x
-* csky ([WIP](https://reviews.llvm.org/D93798))
 * h8300
 * ia64
-* m68k ([WIP](https://reviews.llvm.org/D95315))
 * microblaze
 * nds32
 * nios2