LDO9 and LDO10 were listed with the same enable bits.
That looks insane and there are no provisions in the code for handling such
a special case. Also other out-of-tree drivers use a separate bit to
enable it.
Example:
https://github.com/brunotl/kernel-kobo-mx6sl-ntx/blob/master/drivers/regulator/ricoh619-regulator.c
So it seems to be clearly a bug.
I cannot fully check it on my board without schematics and just discovered
this during code analysis for another problem.