ARM: OMAP4+: Fix DPLL programming sequence

All the output clock parameters of a DPLL needs to be programmed before
locking the DPLL. But it is being configured after locking the DPLL which
could potentially bypass DPLL. So fixing this sequence.

Reported-by: Richard Woodruff <r-woodruff2@ti.com>
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Reviewed-by: Nishanth Menon <nm@ti.com>