tc2: use fip_gpt-tc.bin to support fwu

fip_gpt-tc.bin is the gpt image that has 4 partitions.
1. FIP_A
2. FIP_B
3. FWU-Metadata
4. Bkup-FWU-Metadata

These partitions are needed for the firmware update functionality.

Signed-off-by: Davidson K <davidson.kumaresan@arm.com>
Change-Id: I186dee53d02dd1b22f54045a0709ec479f306b84