src: Update some incorrect config options in comments

This is a trivial patch to fix some comments that were generating
notes in the kconfig lint test.

Signed-off-by: Martin Roth <martin@coreboot.org>
Change-Id: I26a95f17e82910f50c62215be5c29780fe98e29a
Reviewed-on: https://review.coreboot.org/c/coreboot/+/47366
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-by: Furquan Shaikh <furquan@google.com>
Reviewed-by: Christian Walter <christian.walter@9elements.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/drivers/i2c/designware/dw_i2c.h

@@ -17,7 +17,7 @@
 
 /*
  * Timing values are in units of clock period, with the clock speed
- * provided by the SOC in CONFIG_DRIVERS_I2C_DESIGNWARE_I2C_CLOCK_MHZ
+ * provided by the SOC in CONFIG_DRIVERS_I2C_DESIGNWARE_CLOCK_MHZ
  * Automatic configuration is done based on requested speed, but the
  * values may need tuned depending on the board and the number of
  * devices present on the bus.