hw/arm/aspeed_ast27x0-tsp: Change to use Aspeed27x0CoprocessorState

hw/arm/aspeed_ast27x0-tsp: Change to use Aspeed27x0CoprocessorState

Refactor the AST27x0 TSP implementation to use the unified
Aspeed27x0CoprocessorState, matching the prior SSP change and removing the
duplicated Aspeed27x0TSPSoCState.

Key updates:
- Delete Aspeed27x0TSPSoCState and reuse Aspeed27x0CoprocessorState.

Update Ast2700FCState to declare tsp as Aspeed27x0CoprocessorState.
This aligns TSP with SSP on a single coprocessor state type, reducing code
duplication and simplifying maintenance.

No functional change.

Signed-off-by: Jamin Lin <jamin_lin@aspeedtech.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Link: https://lore.kernel.org/qemu-devel/20251013054334.955331-14-jamin_lin@aspeedtech.com
Signed-off-by: Cédric Le Goater <clg@redhat.com>