Update/bugfix hardware ECC config handling.  The driver should still
be able to build without that support enabled (else remove its Kconfig
option!); remove frowned-upon inline #ifdeffery.

Also suffix all the original ECC logic with _1bit to distinguish it
from the DM355's enhanced ECC hardware (corrects 4 single-bit errors
per 512 bytes), which should get good support.

Note that I think the issue with flash access on the DM355 EVM is
likely to be ECC related.  Specifically, the original LSP uses that
enhanced ECC hardware, and thus needs 10 bytes of data per 512 byte
block ... which seems to be stored INLINE rather than in the OOB
region, because of a Linux restriction to 32 bytes of ECC data.
(One hopes that restriction gets lifted ASAP.)
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>