powerpc/epapr: Don't use wrteei on non booke

wrteei is only for booke. Use the standard mfmsr/ori/mtmsr
when non booke.

Reported-by: Jan-Benedict Glaw <jbglaw@lug-owl.de>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/b29c7f1727433b003eae050e44072741c8ac223b.1671475543.git.christophe.leroy@csgroup.eu

Author: chleroy

arch/powerpc/kernel/epapr_hcalls.S

@@ -21,7 +21,13 @@ _GLOBAL(epapr_ev_idle)
 	ori	r4, r4,_TLF_NAPPING	/* so when we take an exception */
 	PPC_STL	r4, TI_LOCAL_FLAGS(r2)	/* it will return to our caller */
 
+#ifdef CONFIG_BOOKE_OR_40x
 	wrteei	1
+#else
+	mfmsr	r4
+	ori	r4, r4, MSR_EE
+	mtmsr	r4
+#endif
 
 idle_loop:
 	LOAD_REG_IMMEDIATE(r11, EV_HCALL_TOKEN(EV_IDLE))