drm/amd: Move helper for dynamic speed switch check out of smu13

commit 18862307 upstream.

This helper is used for checking if the connected host supports
the feature, it can be moved into generic code to be used by other
smu implementations as well.

Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Reviewed-by: Evan Quan <evan.quan@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org # 6.1.x
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>