i82371eb: Remove weak functions

Change-Id: I593f7745f79e7b5dd0f2f0acb7eb6e1b629fc6ca
Signed-off-by: Vladimir Serbinenko <phcoder@gmail.com>
Reviewed-on: http://review.coreboot.org/7376
Tested-by: build bot (Jenkins)
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>