src/include: Wrap lines at 80 columns

Fix the following warning detected by checkpatch.pl:

WARNING: line over 80 characters

Changed a few comments to reduce line length.  File
src/include/cpu/amd/vr.h was skipped.

TEST=Build and run on Galileo Gen2

Change-Id: Ie3c07111acc1f89923fb31135684a6d28a505b61
Signed-off-by: Lee Leahy <Leroy.P.Leahy@intel.com>
Reviewed-on: https://review.coreboot.org/18687
Tested-by: build bot (Jenkins)
Reviewed-by: Martin Roth <martinroth@google.com>
diff --git a/src/include/ip_checksum.h b/src/include/ip_checksum.h
index f6ef560..f2632e7 100644
--- a/src/include/ip_checksum.h
+++ b/src/include/ip_checksum.h
@@ -1,5 +1,6 @@
 #ifndef IP_CHECKSUM_H
 #define IP_CHECKSUM_H
 unsigned long compute_ip_checksum(const void *addr, unsigned long length);
-unsigned long add_ip_checksums(unsigned long offset, unsigned long sum, unsigned long new);
+unsigned long add_ip_checksums(unsigned long offset, unsigned long sum,
+	unsigned long new);
 #endif /* IP_CHECKSUM_H */