Revert "powerpc: Remove unused FW_FEATURE_NATIVE references"

Revert "powerpc: Remove unused FW_FEATURE_NATIVE references"

This reverts commit 79b74a68486765a4fe685ac4069bc71366c538f5.

It broke booting on IBM Cell machines when the kernel is also built with
CONFIG_PPC_PS3=y.

That's because FW_FEATURE_NATIVE_ALWAYS = 0 does have an important
effect, which is to clear the PS3 ALWAYS features from
FW_FEATURE_ALWAYS.

Note that CONFIG_PPC_NATIVE has since been renamed
CONFIG_PPC_HASH_MMU_NATIVE.

Fixes: 79b74a684867 ("powerpc: Remove unused FW_FEATURE_NATIVE references")
Cc: stable@vger.kernel.org # v5.17+
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220823115952.1203106-1-mpe@ellerman.id.au