fix(interrupts): check support for ESPI before testing it

It is possible for extended range interrupts to be enabled by software
but the underlying hardware (GIC) may not support it. In such,
scenarios check if the support exists before exercising the
ESPI functionality.

Signed-off-by: Madhukar Pappireddy <madhukar.pappireddy@arm.com>
Change-Id: Ibdf18be8403539c0ae9204309adc8a81dd0382d3
6 files changed