stm32: dcmi: hook up doxygen again

We still need stub .c files as we're using shared common files, so .d
tracking doesn't work.  It lets us setup basic introductory text anyway,
and there will be .c files eventually, so acceptable.

lib/stm32/common/dcmi_common_f47.c

@@ -0,0 +1,18 @@
+/** @addtogroup dcmi_file DCMI peripheral API
+ * @ingroup peripheral_apis
+ * @brief Digital camera interface.
+ *
+ * The digital camera is a synchronous parallel interface able to
+ * receive a high-speed data flow from an external 8-, 10-, 12- or 14-bit
+ * CMOS camera module.
+ *
+ * If the APIs here are insufficient or incomplete, see @ref dcmi_defines
+ *
+ * LGPL License Terms @ref lgpl_license
+ */
+
+/**@{*/
+
+#include <libopencm3/stm32/dcmi.h>
+
+/**@}*/

lib/stm32/f4/Makefile

@@ -42,6 +42,7 @@ OBJS += can.o
 OBJS += crc_common_all.o
 OBJS += crypto_common_f24.o crypto.o
 OBJS += dac_common_all.o
+OBJS += dcmi_common_f47.o
 OBJS += desig_common_all.o desig_common_v1.o
 OBJS += dma_common_f24.o
 OBJS += dma2d_common_f47.o

lib/stm32/f7/Makefile

@@ -44,6 +44,7 @@ OBJS += adc_common_v1.o adc_common_v1_multi.o adc_common_f47.o
 OBJS += can.o
 OBJS += crc_common_all.o crc_v2.o
 OBJS += dac_common_all.o
+OBJS += dcmi_common_f47.o
 OBJS += desig_common_all.o desig.o
 OBJS += dma_common_f24.o
 OBJS += dma2d_common_f47.o