ARCv2 cores may access data not aligned by the data size boundary.
I.e. read entire 32-bit word from address 0x1.
This feature is configurable for ARC EM cores excluding those with
secure shield 2+2 mode. When it's available in hardware it's required
to enable that feature in run-time as well setting status32.AD bit.
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>