csc: allow compiling with multiple HW types

csc: allow compiling with multiple HW types

Once G2D support is added, the same binary should be usable for either
Gscaler or G2D.  The HW type is controlled through the new property
CSC_HW_PROPERTY_HW_TYPE.

Also return an error if any hardware properties are set after the device
is already opened.  This didn't work before and should never happen, but
it's worth adding a check just in case.

Change-Id: I6d3fab4e777395a7e14a1f54353100902c76f75e
Signed-off-by: Greg Hackmann <ghackmann@google.com>