drm/amdgpu/soc15: add need_reset_on_init asic callback for SOC15 (v2)

SOC15 chips require a reset if the driver was previously loaded
because the PSP can only be loaded once between each reset.

v2: rebase, handle multiple asic funcs

Reviewed-by: Evan Quan <evan.quan@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>