docs: fix simple typo, repeately -> repeatedly

There is a small typo in examples/c/pwm.c, examples/c/spi.c.

Should read `repeatedly` rather than `repeately`.

examples/c/pwm.c

@@ -6,7 +6,7 @@
  * SPDX-License-Identifier: MIT
  *
  * Example usage: Generates PWM signal of period 200us with variable dutycyle
- *                repeately. Press Ctrl+C to exit
+ *                repeatedly. Press Ctrl+C to exit
  */
 
 /* standard headers */

examples/c/spi.c

@@ -6,7 +6,7 @@
  *
  * SPDX-License-Identifier: MIT
  *
- * Example usage: Display set of patterns on MAX7219 repeately.
+ * Example usage: Display set of patterns on MAX7219 repeatedly.
  *                Press Ctrl+C to exit
  */