- On resume all registers have to be initialized again like after
power-on so reset sc_inited in gem_suspend() in order get all of
the registers set next time gem_init_regs() is called.
- On at least some ERI and GEM revisions GEM_MAC_RX_OVERFLOW happen
often due to a silicon bug and re-initializing is all we can do
about these errors so make handling them non-verbose.
- Remove a superfluous memset(3) call in gem_meminit(), all elements
are initialized to 0 anyway.
MFC after: 1 week