style: fix spelling in code comments and strings

drivers/motor/Make.defs

@@ -32,7 +32,7 @@ ifeq ($(CONFIG_MOTOR_UPPER),y)
 CSRCS += motor.c
 endif
 
-# Stepper upper half and lower halfs
+# Stepper upper half and lower halves
 
 ifeq ($(CONFIG_STEPPER_UPPER),y)
 CSRCS += stepper.c

drivers/motor/foc/drv8301.c

@@ -145,7 +145,7 @@ static void drv8301_read(FAR struct drv8301_priv_s *priv, uint8_t addr,
   regval = 0;
   SPI_RECVBLOCK(priv->spi, &regval, 1);
 
-  /* Retrun data */
+  /* Return data */
 
   *data = (regval & 0x7ff);
 

drivers/motor/foc/foc_pwr.c

@@ -62,7 +62,7 @@ int focpwr_initialize(FAR struct focpwr_dev_s *pwr,
   pwr->devno = devno;
   pwr->ops   = ops;
 
-  /* Connet to FOC device */
+  /* Connect to FOC device */
 
   dev->pwr = pwr;