Documentation: Fix formatting

Fix formatting and missing close block quotes in nri_registers.md

Change-Id: I5fa0136f4d7f05737a0d53ff9da7d2c77b22d675
Signed-off-by: Tom Hiller <thrilleratplay@gmail.com>
Reviewed-on: https://review.coreboot.org/28327
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Patrick Rudolph <siro@das-labor.org>
1 file changed