framebuffer-ng: move more hw specific stuff to fbaccel

setMode (not really the right name) is also hardware specific,
so move it into fbaccel, too.

src/driver/fbaccel.h

@@ -63,6 +63,7 @@ class CFbAccel
 		CFbAccel(CFrameBuffer *fb);
 		~CFbAccel();
 		bool init(void);
+		int setMode(void);
 		void paintPixel(int x, int y, const fb_pixel_t col);
 		void paintRect(const int x, const int y, const int dx, const int dy, const fb_pixel_t col);
 		void paintLine(int xa, int ya, int xb, int yb, const fb_pixel_t col);