These processors do not currently support doorbell IPIs, so remove them
from the feature list if we are at DD 1.xx for the 0x004d part.
This fixes a regression caused by d4e58e5928 (powerpc/powernv: Enable
POWER8 doorbell IPIs). With that patch the kernel would hang at boot
when calling smp_call_function_many, as the doorbell would not be
received by the target CPUs:
.smp_call_function_many+0x2bc/0x3c0 (unreliable)
.on_each_cpu_mask+0x30/0x100
.cpuidle_register_driver+0x158/0x1a0
.cpuidle_register+0x2c/0x110
.powernv_processor_idle_init+0x23c/0x2c0
.do_one_initcall+0xd4/0x260
.kernel_init_freeable+0x25c/0x33c
.kernel_init+0x1c/0x120
.ret_from_kernel_thread+0x58/0x7c
Fixes: d4e58e5928 (powerpc/powernv: Enable POWER8 doorbell IPIs)
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
bd6ba3518f