OMAP3: clock: add capability to change rate of dpll4_m5_ck_3630

Add necessary clk_sel definitions to clock framework to allow changing
dpll4_m5_ck_3630 rate. This is used by the ISP driver.

Signed-off-by: Vimarsh Zutshi <vimarsh.zutshi@nokia.com>
[paul@pwsan.com: updated to apply]
Signed-off-by: Paul Walmsley <paul@pwsan.com>