arch/x86/cf9_reset: Fix typo

Change-Id: I4a8d29ab647837965e5341d019664f0ed401639a
Signed-off-by: Elyes HAOUAS <ehaouas@noos.fr>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/38311
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>

src/arch/x86/cf9_reset.c

@@ -35,7 +35,7 @@ void do_system_reset(void)
  * A full reset in terms of the CF9 register triggers a power cycle
  * (i.e. S0 -> S5 -> S0 transition). Thus, it could be called a
  * "cold reset".
- * Note: Not all x86 implementations comply with this defitinion,
+ * Note: Not all x86 implementations comply with this definition,
  *       some may require additional configuration to power cycle.
  */
 void do_full_reset(void)