Exynos542x: Config: Add various configs

This patch adds "iRAM, CPU state and low power" configs
which are the addresses acting as flag registers.

iROM code checks CONFIG_LOWPOWER_FLAG address. If it is equal
to CONFIG_LOWPOWER_EN then it jumps to the address (0x02020000+CPUID*4).
This is a part of iROM logic. Rest other flags are being used at
various places during kernel switching and reset.
They are nowhere documented because they are part programming.
These configs are serving as flags for us because they are
representing the addresses in iRAM which we are using for
storing and extracting CPU Status and GIC status.

Signed-off-by: Akshay Saraswat <akshay.s@samsung.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Tested-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Minkyu Kang <mk7.kang@samsung.com>