Added macro support OS(TIZEN), OS(TIZEN_MOBILE) and OS(TIZEN_TV) for WebKit.

Added macro support OS(TIZEN), OS(TIZEN_MOBILE) and OS(TIZEN_TV) for WebKit.

1) This patch allows to replace statement #if defined(OS_TIZEN_MOBILE) with
statement #if OS(TIZEN_MOBILE). Usage of OS macro is required because
buildbot has presubmit check which dissalow to commit patch which contains
macro which matches to pattern OS_*.
2) Added dependency to library capi-system-system-settings.
Library 'capi-system-system-settings' is used by WebKit project for Tizen build
(WebKit/Source/platform/fonts/skia/FontCacheSkia.cpp). Currently OS(TIZEN) macro
was not working and after fixing macro issue project won't compile, so we
need to fix also dependency.
Reviewed by: Antonio Gomes, Piotr Szawdyński, SeungSeop Park, Tomasz Czekala

Change-Id: I36694bce7090a02e53982c3d936dc4a997377470
Signed-off-by: Piotr Szawdyński <p.szawdynski@samsung.com>
Signed-off-by: Piotr Tworek <p.tworek@samsung.com>