The TIDR SPR only exists on POWER9. Avoid accessing it when the
feature bit for it is not set.
Signed-off-by: NNicholas Piggin <npiggin@gmail.com>
Reviewed-by: NFabiano Rosas <farosas@linux.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211123095231.1036501-3-npiggin@gmail.com