CoT used for BL1 and BL2 are moved to tbbr_cot_bl1.c
and tbbr_cot_bl2.c respectively.
Common CoT used across BL1 and BL2 are moved to
tbbr_cot_common.c.

Signed-off-by: Manish V Badarkhe <Manish.Badarkhe@arm.com>
Change-Id: I2252ac8a6960b3431bcaafdb3ea4fb2d01b79cf5

For the iMX7 SOCs, part of the code for platform
setup implementation can be reused and made
common for all these SoCs. This patch extracts
the common part for reuse.

Signed-off-by: Jun Nie <jun.nie@linaro.org>
Change-Id: I42fd4167e6903416df96a0159a046abf3896e878