[bootlin/training-materials] 0dd17f: kernel: i2c-comm: explain why usleep_range() shoul...

[Clément Léger]

  Branch: refs/heads/master
  Home:   https://github.com/bootlin/training-materials
  Commit: 0dd17f28a2ce65beb9a946f621020448c54b5a83
      https://github.com/bootlin/training-materials/commit/0dd17f28a2ce65beb9a946f621020448c54b5a83
  Author: Clément Léger <clement.leger at bootlin.com>
  Date:   2022-06-21 (Tue, 21 Jun 2022)

  Changed paths:
    M labs/kernel-i2c-communication/kernel-i2c-communication.tex

  Log Message:
  -----------
  kernel: i2c-comm: explain why usleep_range() should be used

There is no real explanation why usleep_range() should be used rather
than a simple usleep(). Add some text to clarify that's it's more
efficient if wait time is flexible.

Signed-off-by: Clément Léger <clement.leger at bootlin.com>