msm: sde: Add error code for unsupported rotator version

Although rotator driver checks for hardware version, and rejects
unsupported version.  But it does not return error code to indicate
error condition, and causes driver crash.

This fix adds error code to unsupported version, so upper layer can
properly handling the condition.

CRs-Fixed: 1015335
Change-Id: If83199b5990a3623b1018058d2164862352902b7
Signed-off-by: Alan Kwong <akwong@codeaurora.org>