Qualcom processors use proprietary bus to talk with PMIC devices -
SPMI (System Power Management Interface).
On wiring level it is similar to I2C, but on protocol level, it's
multi-master and has simple autodetection capabilities.
This commit adds simple uclass that provides bus read/write interface.
Signed-off-by: Mateusz Kulikowski <firstname.lastname@example.org>
Reviewed-by: Simon Glass <email@example.com>
Tested-by: Simon Glass <firstname.lastname@example.org>