OMAP2xxx: clock: remove dsp_irate_ick

After commit 81b34fbecbfbf24ed95c2d80d5cb14149652408f ("OMAP2 clock:
split OMAP2420, OMAP2430 clock data into their own files"), it's
possible to remove dsp_irate_ick from the OMAP2420 and OMAP2430 clock
files.  It was originally only needed due to a 2420/2430 clock tree difference,
and now that the data is in separate files, it's superfluous.

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

diff --git a/arch/arm/mach-omap2/clock.h b/arch/arm/mach-omap2/clock.h
index 62cfd6c..e10ff2b 100644
--- a/arch/arm/mach-omap2/clock.h
+++ b/arch/arm/mach-omap2/clock.h
@@ -139,6 +139,7 @@
 extern const struct clksel_rate gpt_32k_rates[];
 extern const struct clksel_rate gpt_sys_rates[];
 extern const struct clksel_rate gfx_l3_rates[];
+extern const struct clksel_rate dsp_ick_rates[];
 
 #if defined(CONFIG_ARCH_OMAP2) && defined(CONFIG_CPU_FREQ)
 extern void omap2_clk_init_cpufreq_table(struct cpufreq_frequency_table **table);