atspi: find the first, last obj using "GetNeighbor"

atspi: find the first, last obj using "GetNeighbor"

The reducing IPC task overlooked functionality to get the first, last object.
This commit is related to the following commit.

[screen-reader]
commit 72e3396fac3a377f49422af454875a0e4c9a58bc

Add loop navigation feature.

Screen reader gives FOCUS_CHAIN_END_NOTIFICATION_EVENT notification if there is
no more object in its direction. If user gives next(or prev) gesture in same
direction one more time, then the first(or last) object will grab highlight.

Change-Id: I0e68c84a595396cbf7d0d2ae4d93fca4c425f0ea