drivers: misc: ethos_u: support nuvoton numaker m55m1x

This adds frontend of arm ethos-u core driver for nuvoton numaker m55m1x.
Special notes include:
1. Leaving application overriding dcache flush/invalidate weak functions
   for cacheable NPU buffer
2. Configuring macs_per_cc to 256 in arm ethos-u core driver to match
   m55m1x ethos-u RTL config

Signed-off-by: Chun-Chieh Li <ccli8@nuvoton.com>