powerpc/64s: Don't set FSCR bits in INIT_THREAD

Since the previous commit that saves the value of FSCR configured at
boot into init_task.thread.fscr, the static initialisation in
INIT_THREAD now no longer has any effect.

So remove it.

For non DT CPU features, the end result is the same, because
__init_FSCR() is called on all CPUs that have an FSCR (Power8,
Power9), and it sets FSCR_TAR & FSCR_EBB.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200527145843.2761782-4-mpe@ellerman.id.au

arch/powerpc/include/asm/processor.h

@@ -302,7 +302,6 @@ struct thread_struct {
 	.ksp = INIT_SP, \
 	.addr_limit = KERNEL_DS, \
 	.fpexc_mode = 0, \
-	.fscr = FSCR_TAR | FSCR_EBB \
 }
 #endif