(split) ext2fs: Re-enable reallocblk.

The major corruption issues affecting this code have been fixed
a while ago.

MFC after:	1 week
(split) Fix a range check for maximum transmit length. The existing code was
off by 4 bytes in one case.

Approved by:	kevlo @
MFC after:	2 weeks
(split) Correct setting R92C_TXAGC_MCS11_MCS08 register.
(split) Merge branch 'CURRENT' (commit '06622912')