feat: add PS2 interface support and refactor related components

- Updated the PS2 interface in the APB wrapper to include RX and TX FIFO depths.
- Replaced the kdb_model with ps2_device_model in the testbench for better PS2 handling.
- Added new PS2 source files and headers for keyboard and mouse functionality.
- Refactored GPIO alternate functions to support PS2 clock and data signals.
- Implemented PS2 decoder tests for keyboard and mouse in the runtime tests.
- Updated the software makefile to include new PS2 source files and headers.
- Modified the topology tests to validate PS2 GPIO assignments.

tests/test_soc_topology.py

@@ -83,6 +83,10 @@ def test_topology_generates_complete_rib_apb_and_gpio_bindings(tmp_path: Path) -
     assert "assign u_sdio_ribp_if.valid = 1'b0;" in routes
     assert gpio.count("// GPIO") == 64
     assert "assign u_uart1_if.rx_i = u_gpio_if.di_i[0];" in gpio
+    assert "assign u_gpio_if.alt1_do_i[0] = u_ps2_if.ps2_clk_o;" in gpio
+    assert "assign u_gpio_if.alt1_oe_i[0] = u_ps2_if.ps2_clk_oe_o;" in gpio
+    assert "assign u_gpio_if.alt1_do_i[1] = u_ps2_if.ps2_dat_o;" in gpio
+    assert "assign u_gpio_if.alt1_oe_i[1] = u_ps2_if.ps2_dat_oe_o;" in gpio
     assert "assign u_gpio_if.alt1_do_i[2] = u_ws2812_if.dat_o;" in gpio
     assert "assign u_gpio_if.alt1_do_i[22] = u_psram_if.nss_o[0];" in gpio
     assert apb_interfaces.count("apb4_if u_") == 10