refactor(imx8mq): introduce BL31_SIZE

No functional change.

Introduce BL31_SIZE define and calculate the limits based on the
BL31_BASE and the BL31_SIZE define. Also make use of SZ_64K to make
it easier to read. This is required for later BL31 PIE support since
it drops the calculation based on the BL31_LIMIT and BL31_BASE.

Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Change-Id: I517074b866b5bf11841b51777f87c926b304488d
2 files changed