hdq: bQ27000 HDQ Slave Interface Driver

Provide the BQ27000 slave interface driver.

Signed-off-by: Madhusudhan <Chikkature&lt;madhu.cr@ti.com>
Acked-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>