powerpc/64s/idle: Fix restore of AMOR on POWER9 after deep sleep

[ Upstream commit c1b25a17 ]

POWER8 restores AMOR when waking from deep sleep, but POWER9 does not,
because it does not go through the subcore restore.

Have POWER9 restore it in core restore.

Fixes: ee97b6b9 ("powerpc/mm/radix: Setup AMOR in HV mode to allow key 0")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

arch/powerpc/kernel/idle_book3s.S

@@ -838,6 +838,8 @@ BEGIN_FTR_SECTION
 	mtspr	SPRN_PTCR,r4
 	ld	r4,_RPR(r1)
 	mtspr	SPRN_RPR,r4
+	ld	r4,_AMOR(r1)
+	mtspr	SPRN_AMOR,r4
 END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300)
 
 	ld	r4,_TSCR(r1)