watchdog: tegra: get expiry count from DT

watchdog: tegra: get expiry count from DT

The total expiry count of Tegra WDTs is limited to HW design and depends
on skip configuration if supported. This change adds support to get the
expiry count through device tree. To be safe, we set the default expiry
count to 1, in case device tree doesn't provide the value.

(adapted from commit 9a947bd96bd93cd8e81217fc9ad5eeb0bb2e1e9f)

Bug 200314562

Change-Id: I50316bf34df8d63fe660c46c6baecc85276859e2
Signed-off-by: Allen Yu <alleny@nvidia.com>
Signed-off-by: Shreshtha SAHU <ssahu@nvidia.com>
Reviewed-on: https://git-master/r/1515194
GVS: Gerrit_Virtual_Submit
Reviewed-by: Bibek Basu <bbasu@nvidia.com>
Tested-by: Bibek Basu <bbasu@nvidia.com>