clocksource/drivers/timer-tegra186: Correct num_wdts for Tegra186 and Tegra234

clocksource/drivers/timer-tegra186: Correct num_wdts for Tegra186 and Tegra234

On Tegra186 and Tegra234, WDT2 is connected to the Audio Processing
Engine (APE) and cannot be accessed from Linux. Only WDT0 and WDT1
are accessible to Linux.

Update num_wdts from 3 to 2 for both Tegra186 and Tegra234 to reflect
the actual number of watchdogs available to Linux.

Signed-off-by: Kartik Rajput <kkartik@nvidia.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@kernel.org>
Reviewed-by: Jon Hunter <jonathanh@nvidia.com>
Link: https://patch.msgid.link/20260507154557.2082697-3-kkartik@nvidia.com