CCN: Add API to query the PART0 ID from CCN

CCN: Add API to query the PART0 ID from CCN

This patch adds the API `ccn_get_part0_id` to query the PART0 ID from the
PERIPHERAL_ID 0 register in the CCN driver. This ID allows to distinguish
the variant of CCN present on the system and possibly enable dynamic
configuration of the IP based on the variant. Also added an assert in
`ccn_master_to_rn_id_map()` to ensure that the master map bitfield provided
by the platform is within the expected interface id.

Change-Id: I92d2db7bd93a9be8a7fbe72a522cbcba0aba2d0e