ARM: OMAP2+: clock/dpll: remove unused header includes from clkt_dpll.c

Some of the machine specific header includes are no longer used, so remove
these from the source file. This allows migration of the file under clock
driver.

Signed-off-by: Tero Kristo <t-kristo@ti.com>
Reviewed-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Paul Walmsley <paul@pwsan.com>