fix(n1sdp): fix spi_ids range for n1sdp multichip boot

According to GIC-600 TRM, it supports upto 960 SPIs.
This patch configures the SPI IDs range to 32-991, and distributes
them equally across both the chips.

Signed-off-by: sahil <sahil@arm.com>
Change-Id: I814cdadb59c8765c239ae0375e547718b7f208ff
1 file changed