Revert "arm64: smccc: Remove broken support for SMCCCv1.3 SVE discard hint"

This reverts commit bfcaffd4 which is
commit 8c462d56 upstream.

It breaks the Android kernel abi and can be brought back in the future
in an abi-safe way if it is really needed.

Bug: 161946584
Change-Id: I8936edc25779838c941ebaf55f267f386d876403
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>