Blacklist constantly failing test case on Mac OS X

tst_qdeclarativetextinput fails on Mac OS X

Task-number: QTBUG-41316
Change-Id: I86724ecf0196ab4728f3bf14fcfc6cfe18bc20d1
Reviewed-by: Lars Knoll <lars.knoll@digia.com>
Merge remote-tracking branch 'origin/5.4' into dev

Change-Id: I51b5541943de39d87eed4887a879eeacb3a7e376