drm/amd/pm/smu13: Remove unused smu_v3 functions

smu_v13_0_display_clock_voltage_request() and
smu_v13_0_set_min_deep_sleep_dcefclk() were added in 2020 by
commit c05d1c40 ("drm/amd/swsmu: add aldebaran smu13 ip support (v3)")
but have remained unused.

Remove them.

smu_v13_0_display_clock_voltage_request() was the only user
of smu_v13_0_set_hard_freq_limited_range().  Remove it.

Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>