powerpc: Fix merge conflict between pcrel and copy_thread changes

Fix a conflict between commit 4e991e3c ("powerpc: add CFUNC
assembly label annotation") and commit b504b6aa ("powerpc:
differentiate kthread from user kernel thread start").

Fixes: 4e991e3c ("powerpc: add CFUNC assembly label annotation")
Fixes: b504b6aa ("powerpc: differentiate kthread from user kernel thread start")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230426055848.402993-2-npiggin@gmail.com