arm: atmel: cpux9k2: add missing cache configs

* add CONFIG_SYS_CACHELINE_SIZE to eb_cpux9k2 board config header
* dissable dcache (CONFIG_SYS_DCACHE_OFF) for eb_cpux9k2

Signed-off-by: Jens Scharsig (BuS Elektronik) <esw@bus-elektronik.de>
1 file changed