ARM: OMAP2+: clock/dpll: convert bypass check to use clk_features

OMAP2 DPLL code for checking whether DPLL is in bypass mode now uses
clk_features data provided during boot. This avoids the need to use
cpu_is_X type checks runtime, and allows us to eventually move the
clock code under the 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>