clk: add clk_get_freq method

Adds implementation of clk_get_freq method.
It allows to retrieve clock frequency in Hz
based on provided clock id.

Signed-off-by: Tomasz Lauda <tomasz.lauda@linux.intel.com>

src/include/sof/clk.h

@@ -53,6 +53,8 @@ struct freq_table {
 	uint32_t enc;
 };
 
+uint32_t clock_get_freq(int clock);
+
 void clock_set_freq(int clock, uint32_t hz);
 
 uint64_t clock_ms_to_ticks(int clock, uint64_t ms);

src/lib/clk.c

@@ -83,6 +83,11 @@ static inline uint32_t clock_get_nearest_freq_idx(const struct freq_table *tab,
 	return size - 1;
 }
 
+uint32_t clock_get_freq(int clock)
+{
+	return clk_pdata->clk[clock].freq;
+}
+
 void clock_set_freq(int clock, uint32_t hz)
 {
 	struct notify_data notify_data;