ARC: cache: define CONFIG_SYS_CACHELINE_SIZE as ARCH_DMA_MINALIGN

Even though we don't use CONFIG_SYS_CACHELINE_SIZE in ARC-specific code
it is used a lot in different drivers for alignment purposes.

So we define it and make much more drivers at least compilable for ARC.

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>