nx2: run the guest counter at 31.25 MHz for Switch 2 titles

The Switch 2 counter runs at 31.25 MHz and its SDK converts ticks with
that constant: Mario Kart World's sdk builds 31,250,000 in
nn::os::GetSystemTickFrequency, TickManager::ConvertToTimeSpan and
TickManager::ConvertToTick (19.2 MHz appears nowhere). Eglantine counted
at the Switch 1 rate for every title, so every tick-based time in a
Switch 2 game was off by 1.63x: elapsed times read short, and a deadline
of one 60 Hz frame converted to ticks waited ~27 ms.

The wall clock now has a guest counter frequency, set at boot: 31.25 MHz
for Switch 2 programs, 19.2 MHz otherwise, EDEN_NX2_CNTFRQ=<Hz> to force
one. CNTPCT reads, CNTFRQ_EL0, svcGetSystemTick, thread tick counts and
the time services' tick conversions follow it, and the CNTPCT spin
detection keeps its ~1.7 us threshold.

Mario Kart World, title screen and attract demo, 180 s, same build:
frame times unchanged (17-19 ms once warm), process CPU time 848 s
instead of 930 s.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/core/core_timing.cpp b/src/core/core_timing.cpp
index b85bd30a58..dfc3f6f2a6 100644
--- a/src/core/core_timing.cpp
+++ b/src/core/core_timing.cpp
@@ -224,7 +224,7 @@ void CoreTiming::ResetTicks() {
 }
 
 u64 CoreTiming::GetClockTicks() const {
-    u64 fres = is_multicore ? Common::g_wall_clock.GetCNTPCT() : Common::WallClock::CPUTickToCNTPCT(cpu_ticks);
+    u64 fres = is_multicore ? Common::g_wall_clock.GetCNTPCT() : Common::g_wall_clock.CPUTickToGuestCNTPCT(cpu_ticks);
     if (const u32 target = CpuClockTargetMhz(Settings::values.cpu_clock.GetValue());
         target != CPU_CLOCK_BASE_MHZ) {
         fres = fres * target / CPU_CLOCK_BASE_MHZ;