driver: crypto: SHA: npcx: change to support npcx4

The pre-alloacted size of the buffer for the SHA ROM API code increases
in npcx4 chip. This commit adds a new property context-buffer-size to
sha0 DT node in npcx9 and npcx4 separately. The driver can pre-allocate
buffer with the correct size based on the property.

Signed-off-by: Jun Lin <CHLin56@nuvoton.com>