Description: powerpc/tm: Fix restoring FP/VMX facility incorrectly on interrupts
References:
 https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1843533
Notes:
 carnil> Commit fixes a7771176b439 ("powerpc: Don't enable FP/Altivec if
 carnil> not checkpointed") in 4.15-rc1. Fix can be defered to point
 carnil> release when updating to new upstream stable versions as we
 carnil> disable CONFIG_PPC_TRANSACTIONAL_MEM since 5.2.6-1 (sid),
 carnil> 4.19.67-2 (buster).
Bugs:
upstream: released (5.3-rc8) [a8318c13e79badb92bc6640704a64cc022a6eb97]
4.19-upstream-stable: released (4.19.73) [569775bd536416ed9049aa580d9f89a0b4307d60]
4.9-upstream-stable: N/A "Vulnerable code introduced later"
3.16-upstream-stable: N/A "Vulnerable code introduced later"
sid: released (5.2.17-1)
4.19-buster-security: released (4.19.87-1)
4.9-stretch-security: N/A "Vulnerable code introduced later"
3.16-jessie-security: N/A "Vulnerable code introduced later"