refactor(plat/marvell/a3k): Rename *_CFG and *_SIG variables

For TIM config file use TIM name instead of DOIMAGE and use underscores
to make variable names more readable.

Signed-off-by: Pali Rohár <pali@kernel.org>
Change-Id: I1282ce11f1431c15458a143ae7bfcee85eed2432
1 file changed