Revert "powerpc: Remove unused FW_FEATURE_NATIVE references"

Revert "powerpc: Remove unused FW_FEATURE_NATIVE references"

This reverts commit 4a78c707622612b0cd9c4b681f83494029e0fe58.

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: 4a78c7076226 ("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