davinci: add support for CDCE949 clock synthesizer

This patch adds support for TI's CDCE949 - a clock
synthesizer with 4 PLLs and 9 outputs.

It is used on DM6467 EVM. On the EVM, it generates
clocks required for VPIF, TSIF and Audio modules.

This patch adds it as part of the DaVinci clock framework.

Testing:
The various frequency outputs on Y1 have been tested using
a out-of-tree VPIF video driver supporting HD video.
The register values for Y5 frequency outputs have been
derived from TSIF driver sources in MontaVista LSP kernel,
but actual output has not been tested for lack of TSIF
driver which actually works on the latest kernel.

Signed-off-by: Nageswari Srinivasan <nageswari@ti.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>