feat(tc): allow secure watchdog timer to trigger periodically

feat(tc): allow secure watchdog timer to trigger periodically

This patch does the following:
  1. Configures SBSA secure watchdog timer as Group0 interrupt for
     TC platform while keeping it as Group1 secure interrupt for
     other CSS based SoCs.
  2. Programs the watchdog timer to trigger periodically
  3. Provides a Group0 interrupt handler for TC platform port to
     deactivate the EL3 interrupt due to expiry of secure watchdog
     timer and refresh it explicitly.

Change-Id: I3847d6eb7347c6ea0e527b97b096119ca1e6701b
Signed-off-by: Madhukar Pappireddy <madhukar.pappireddy@arm.com>