Fix typos

Comments only. No functional changes.

include/nuttx/board.h

@@ -182,7 +182,7 @@ void board_late_initialize(void);
  *         implementation without modification.  The argument has no
  *         meaning to NuttX; the meaning of the argument is a contract
  *         between the board-specific initialization logic and the
- *         matching application logic.  The value cold be such things as a
+ *         matching application logic.  The value could be such things as a
  *         mode enumeration value, a set of DIP switch switch settings, a
  *         pointer to configuration data read from a file or serial FLASH,
  *         or whatever you would like to do with it.  Every implementation

include/sys/boardctl.h

@@ -72,7 +72,7 @@
  *                The argument has no meaning to NuttX; the meaning of the
  *                argument is a contract between the board-specific
  *                initialization logic and the matching application logic.
- *                The value cold be such things as a mode enumeration value,
+ *                The value could be such things as a mode enumeration value,
  *                a set of DIP switch switch settings, a pointer to
  *                configuration data read from a file or serial FLASH, or
  *                whatever you would like to do with it.  Every