in PR port-alpha/36628:
- make jensenio_eisa_maxslots() return 8 (instead of 16) since
EISA config for slot 8-15 on jensen could return invalid values
- pass eisa_chipset_tag_t to eisa_init() and check eisa_maxslots()
on probing EISA config space
- pass M_ZERO to malloc(9) and make sure malloc(9) doesn't fail
- fix typo in a debug printf, add more debug printfs, and
use #ifdef EISA_DEBUG to enable them
- cast uint8_t value to uint32_t before shift more than 8 bits
- check buffer region on reading compressed data from EISA config space