include: add missing errno.h

Some files were using errno codes without including errno.h.

Signed-off-by: Gerard Marull-Paretas <gerard.marull@nordicsemi.no>

drivers/mipi_dsi/mipi_dsi.c

@@ -4,6 +4,8 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
+#include <errno.h>
+
 #include <zephyr/drivers/mipi_dsi.h>
 
 ssize_t mipi_dsi_generic_read(const struct device *dev, uint8_t channel,