xtensa: add missing isync to the cpu_reset TLB code

commit cd8869f4cb257f22b89495ca40f5281e58ba359c upstream.

ITLB entry modifications must be followed by the isync instruction
before the new entries are possibly used. cpu_reset lacks one isync
between ITLB way 6 initialization and jump to the identity mapping.
Add missing isync to xtensa cpu_reset.

Cc: stable@vger.kernel.org
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/xtensa/kernel/setup.c b/arch/xtensa/kernel/setup.c
index a285fbd..15580e4 100644
--- a/arch/xtensa/kernel/setup.c
+++ b/arch/xtensa/kernel/setup.c
@@ -515,6 +515,7 @@
 				      "add	%2, %2, %7\n\t"
 				      "addi	%0, %0, -1\n\t"
 				      "bnez	%0, 1b\n\t"
+				      "isync\n\t"
 				      /* Jump to identity mapping */
 				      "jx	%3\n"
 				      "2:\n\t"