phy: cadence-torrent: Explicitly request exclusive reset control

No functional change. Since the reset controls obtained in
Torrent is exclusively used by the Torrent device, use
exclusive reset control request API calls.

Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Reviewed-by: Swapnil Jakhade <sjakhade@cadence.com>
Link: https://lore.kernel.org/r/20210330110138.24356-5-kishon@ti.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>