Add support for platform specific warm-reset through psci system reset 2.

- system_reset2 implementation that calls for l2 cache reset
- Check for magic number and request for warm reset in bl2
- Create a shared reset manager header file for Agilex and Stratix 10
- Clean up parameter info in plat_get_next_bl_params
Signed-off-by: Hadi Asyrafi <muhammad.hadi.asyrafi.abdul.halim@intel.com>
Change-Id: I3fdd9a2711c80d9bd3dc05b81527781d840bd726