STM32: moved timer_ic_set_polarity from timer_common_all to

f1/timer.
Added timer_ic_set_polarity to timer_common_f24 with
the enum tim_ic_pol now including trigger on both edges.
Changed timer_slave_set_polarity to use enum tim_et_pol
rather than tim_ic_pol.

In response to suggestion of stinkydiver73 on 24 March that
timers in all families have an option for triggers on both
edges, except F1.

include/libopencm3/stm32/f1/timer.h

@@ -37,4 +37,18 @@ LGPL License Terms @ref lgpl_license
 
 #include <libopencm3/stm32/common/timer_common_all.h>
 
+/** Input Capture input polarity */
+enum tim_ic_pol {
+	TIM_IC_RISING,
+	TIM_IC_FALLING,
+};
+
+/* --- Function prototypes ------------------------------------------------- */
+
+BEGIN_DECLS
+
+void timer_ic_set_polarity(u32 timer, enum tim_ic_id ic, enum tim_ic_pol pol);
+
+END_DECLS
+
 #endif