Add libm to eliminate "undefined reference to sqrt" on arm 'softfp' builds.
Fix build with asr driver

This was broken by r274819 as asr is not in GENERIC because its not 64bit
safe.

MFC after:	1 month
X-MFC-With:	r274819
Sponsored by:	Multiplay
For both iSCSI initiator and target increase socket buffer sizes before
establishing connection.

This is a workaround for Chelsio TOE driver, that does not update socket
buffer size in hardware after connection established, and unless that is
done beforehand, kernel code will stuck, attempting to send/receive full
PDU at once.

MFC after:	1 week