ARM: OMAP4: clock data: div_iva_hs_clk is a power-of-two divider

The OMAP4 clock divider "div_iva_hs_clk" is listed in the clock data
as an OMAP HSDIVIDER, but it's actually a power-of-two divider.  This
causes a warning during boot on an OMAP4460 Pandaboard-ES with a
recent u-boot:

WARNING: at arch/arm/mach-omap2/clkt_clksel.c:143 omap2_clksel_recalc+0xf4/0x12c()
clock: div_iva_hs_clk: could not find fieldval 0 for parent dpll_core_m5x2_ck

Fix by converting the data for this clock to a power-of-two divider.

Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Mike Turquette <mturquette@linaro.org>