[verilator] Minor verilator updates to reflect clock division

- this change is temporary, need to split into different clocks

Signed-off-by: Timothy Chen <timothytim@google.com>

[sw] Minor updates to software to pass tests

- Increase dif_rv_timer_sanity_test deadline since each tick now counts 4x.
  Without increasing the deadline, the interrupt fires in the middle of a uart print and the test never completes.

Signed-off-by: Timothy Chen <timothytim@google.com>

[verilator, sw] update for verilator frequency change

Signed-off-by: Timothy Chen <timothytim@google.com>

hw/top_earlgrey/rtl/top_earlgrey_verilator.sv

diff --git a/hw/top_earlgrey/rtl/top_earlgrey_verilator.sv b/hw/top_earlgrey/rtl/top_earlgrey_verilator.sv
index 8642694..6a1d940 100644
--- a/hw/top_earlgrey/rtl/top_earlgrey_verilator.sv
+++ b/hw/top_earlgrey/rtl/top_earlgrey_verilator.sv
@@ -150,7 +150,7 @@
   // Both baud rate and frequency must match the settings used in the on-chip
   // software.
   uartdpi #(
-    .BAUD('d9_600),
+    .BAUD('d7_200),
     .FREQ('d500_000)
   ) u_uart (
     .clk_i  (clk_i),

sw/device/lib/arch/device_sim_verilator.c

diff --git a/sw/device/lib/arch/device_sim_verilator.c b/sw/device/lib/arch/device_sim_verilator.c
index c98f462..859d048 100644
--- a/sw/device/lib/arch/device_sim_verilator.c
+++ b/sw/device/lib/arch/device_sim_verilator.c
@@ -13,11 +13,11 @@
 
 const uint64_t kClockFreqCpuHz = 500 * 1000;  // 500kHz
 
-const uint64_t kClockFreqPeripheralHz = 500 * 1000;  // 500kHz
+const uint64_t kClockFreqPeripheralHz = 125 * 1000;  // 125kHz
 
 const uint64_t kClockFreqUsbHz = 500 * 1000;  // 500kHz
 
-const uint64_t kUartBaudrate = 9600;
+const uint64_t kUartBaudrate = 7200;
 
 // Defined in `hw/top_earlgrey/top_earlgrey_verilator.core`
 const uintptr_t kDeviceStopAddress = 0x10008000;

sw/device/tests/dif/dif_rv_timer_sanitytest.c

diff --git a/sw/device/tests/dif/dif_rv_timer_sanitytest.c b/sw/device/tests/dif/dif_rv_timer_sanitytest.c
index 93d1cff..9bbe94a 100644
--- a/sw/device/tests/dif/dif_rv_timer_sanitytest.c
+++ b/sw/device/tests/dif/dif_rv_timer_sanitytest.c
@@ -86,8 +86,8 @@
   CHECK(dif_rv_timer_counter_set_enabled(&timer, kHart, kDifRvTimerEnabled) ==
         kDifRvTimerOk);
 
+  LOG_INFO("Waiting...");
   while (!irq_fired) {
-    LOG_INFO("Waiting...");
     wait_for_interrupt();
   }