EP11: some README updates about usage and restrictions.
EP11: some README updates about usage and restrictions.

Signed-off-by: Joy Latten <d52cec510126fd47fd8d2fded238791e9e5bd0bf@linux.vnet.ibm.com>

joylatten/opencryptoki,fingunter/OpenCryptoki,fingunter/OpenCryptoki,joylatten/opencryptoki,fingunter/OpenCryptoki,joylatten/opencryptoki,joylatten/opencryptoki,fingunter/OpenCryptoki,joylatten/opencryptoki