Don't know if {R|M}STP is enabled or not on your Switch...but, generally, to enable the immediate transition to the forwarding state for a (known) Edge port on a Switch that has STP enabled you would use a command like:
spanning-tree <port-list> admin-edge-port
Syntax:
[no] spanning-tree <port-list> admin-edge-port
Enables admin-edge-port on ports connected to end nodes. During spanning tree establishment, ports with admin-edge-port enabled transition immediately to the forwarding state. If a bridge or switch is detected on the segment, the port automatically operates as non-edge, not enabled.
Default: Disabled
If admin-edge-port is disabled on a port and auto-edge-port has not been disabled, the auto-edge-port setting controls the behavior of the port.
The no form of this command disables edge port operation on the specified ports.
There is also spanning-tree forward-delay (default: 15 seconds)...which sets time that the Switch waits between transitioning from listening to learning and from learning to forwarding states...so, probably, you could also change (lower) that time down to 4 seconds (which is the minimum admitted, if enough for your scenario)...if you don't want to set that port as an admin-edge-port instead of the default auto-edge-port.