fix(n1sdp): configure platform specific secure SPIs

Previous implementation used common CSS interrupts, which do not match
the N1SDP platform interrupt map. Updated to configure Secure
interrupts according to the N1SDP TRM and InfraSYSDESIGN4.0
specification. Additionally, unused definitions from legacy interrupt
configuration are removed.

Signed-off-by: Werner Lewis <werner.lewis@arm.com>
Change-Id: I3dd4bcd4875e138057c62d937572d446b8f88471
1 file changed