mainboards: Remove floating __PRE_RAM__ comments

Change-Id: I110e54175a81b6a651213e0f18ddc1e3e71160cf
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/34920
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>

src/mainboard/packardbell/ms2290/romstage.c

@@ -16,8 +16,6 @@
  * GNU General Public License for more details.
  */
 
-/* __PRE_RAM__ means: use "unsigned" for device, not a struct.  */
-
 #include <stdint.h>
 #include <arch/io.h>
 #include <device/pci_ops.h>