ARM: S5PV210: Add support for VPLL

This patch adds the following.

1. Adds 'clk_sclk_hdmi27m' clock to represent the HDMI 27MHz clock.
2. Adds 'clk_vpllsrc; clock of type clksrc_clk to represent the
   input clock for VPLL.
3. Adds 'clk_sclk_vpll' clock of type clksrc_clk to represent the
   output of the MUX_VPLL mux.
4. Add clk_sclk_hdmi27m, clk_vpllsrc and clk_sclk_vpll to the list
   of clocks to be registered.
5. Adds boot time print of 'clk_sclk_vpll' clock rate.
6. Adds 'clk_fout_vpll' clock to plat-s5p such that it is reusable
   on other s5p platforms.

Signed-off-by: Thomas Abraham <thomas.ab@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>