MFC r260886, r261165, r261171, r261172, r261214
Fix gcc with -Wstrict-prototypes by telling it bi_emac takes no
parameters.
Bus space handles need to be the VA of the requested resource, not the
rounded page VA. Correct so the DBGU device can be mapped for FDT
console since it isn't on a page boundary.
Make early printf output nicer by inserting a carriage return before
any linefeeds that are output.
Before resetting the USART, delay a bit to allow the transmitter to
finish the current character to drain to avoid glitching. Also,
simplify the code a smidge.
Remove extra parens to silence clang warning.
git-svn-id: svn://svn.freebsd.org/base/stable/10@266097
ccf9f872-aa2e-dd11-9fc8-
001c23d0bc1f