refactor: refactor RTL paths and update test descriptions

- Updated RTL paths in various files to remove the 'ribp' prefix, reflecting the new directory structure.
- Modified test descriptions to remove version indicators (e.g., V2, V3) for clarity and consistency.
- Adjusted file references in scripts and tests to align with the new peripheral and multimedia directory structure.
- Added a new test to ensure repository layout invariants, confirming the absence of deprecated paths.

tests/rtl/dvp_tb.sv

@@ -128,7 +128,7 @@ module dvp_tb;
     write(32'h0000_0048, 32'h0000_0004);
     read(32'h0000_003c, value);
     if (ribp.resp_err) $fatal(1, "DVP interrupt read failed");
-    $display("RIBP DVP V2 capture test passed");
+    $display("RIBP DVP capture test passed");
     $finish;
   end
 endmodule

tests/rtl/gpio_tb.sv

@@ -168,7 +168,7 @@ module gpio_tb;
     write_register(ADMIN_BASE + `RIBP_GPIO_ADMIN_OE_CLEAR, 32'h1, 1'b1);
     if (gpio.oe_o[0] !== 1'b1) $fatal(1, "configuration lock did not protect OE");
 
-    $display("GPIO V2 directed test passed");
+    $display("GPIO directed test passed");
     $finish;
   end
 endmodule

tests/rtl/i2c_tb.sv

@@ -302,7 +302,7 @@ module i2c_tb;
     if (i2c.scl_o !== 1'b0 || i2c.sda_o !== 1'b0) begin
       $fatal(1, "I2C pads are not open-drain constants");
     end
-    $display("I2C V2 transfer, error, stretch, arbitration, and recovery test passed");
+    $display("I2C transfer, error, stretch, arbitration, and recovery test passed");
     $finish;
   end
 

tests/rtl/timer_tb.sv

@@ -169,7 +169,7 @@ module timer_tb;
     if ((intr_state[2:1] != 2'b11) || !irq_o) $fatal(1, "interrupt test failed");
     ribp_write(32'h0000_0020, 32'h0000_0007, 4'h1, 1'b0);
 
-    $display("RIBP Timer V2 register, mode, interrupt, and error test passed");
+    $display("RIBP Timer register, mode, interrupt, and error test passed");
     $finish;
   end
 endmodule

tests/rtl/uart_tb.sv

@@ -234,7 +234,7 @@ module uart_tb;
     write_ok(`RIBP_UART_DMA_CTRL, 3);
     if (!dma_tx_stall || !dma_rx_stall) $fatal(1, "Disabled UART asserted a DMA request");
 
-    $display("UART V3 register, FIFO, loopback, flow-control, interrupt, and DMA test passed");
+    $display("UART register, FIFO, loopback, flow-control, interrupt, and DMA test passed");
     $finish;
   end