STM32 battery-backed RAM is organized in 4 byte registers. Number of
registers can vary between models from 5 to 32 registers.
Usually, the registers are part of RTC. On some variants they are part
of tamper module. On STM32F1 the registers are in separate module. For
now, only backup registers from RTC are supported.
Signed-off-by: Patryk Duda <pdk@semihalf.com>
Note that the it8xxx2 does not support a status register so that
functionality is omitted.
This change also adds driver tests that build both the npcx and it8xxx2
drivers.
Signed-off-by: Yuval Peress <peress@chromium.org>
