OMAP3 DPLL: reorganize static functions

Move all static functions up to the top of the file to match the
practice in other OMAP clock code.  Make omap3_noncore_dpll_program()
static (noted by sparse) and prepend an underscore to the function
name to mark that it is file-local.

Signed-off-by: Paul Walmsley <paul@pwsan.com>