Fix common misspellings

Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c
index 7635379..47cadf4 100644
--- a/drivers/tty/serial/omap-serial.c
+++ b/drivers/tty/serial/omap-serial.c
@@ -13,7 +13,7 @@
  * the Free Software Foundation; either version 2 of the License, or
  * (at your option) any later version.
  *
- * Note: This driver is made seperate from 8250 driver as we cannot
+ * Note: This driver is made separate from 8250 driver as we cannot
  * over load 8250 driver with omap platform specific configuration for
  * features like DMA, it makes easier to implement features like DMA and
  * hardware flow control and software flow control configuration with