arm: exynos: Map iRAM APM area for Exynos850 SoC

This iRAM APM area is needed for I3C access to PMIC via APM block.
Without this mapping any access to APM iRAM leads to "Synchronous Abort"
exception.

Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org>
Signed-off-by: Minkyu Kang <mk7.kang@samsung.com>