zephyr: npcx: get valid bit-depth of RAM_PD registers via DT macro
zephyr: npcx: get valid bit-depth of RAM_PD registers via DT macro

Use DT macro to get valid bit-depth of RAM_PD registers instead of a
constant value. Since it is a general solution for saving power in
no-psl mode, this CL replaces the prefix 'NPCX7_' with 'NPCX_'.

BUG=b:188409672
BRANCH=none
TEST=Build and flash on lazor and npcx9 evb. Hibernate lazor platform
by typing 'hibernate' console command. Then, wake it up via lid open.

Signed-off-by: Mulin Chao <6bbc5af053a1dfdc363be6857f30de4ac3bcbd16@nuvoton.com>
Change-Id: Iaf19761cc16f992cfcf06077ac222637e2544e5f
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2948708
Reviewed-by: Keith Short <f6d578f97033c25f1206cb57d52f358974c82954@chromium.org>
Commit-Queue: Keith Short <f6d578f97033c25f1206cb57d52f358974c82954@chromium.org>

coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec