[prim] correct interface documentation.
[prim] correct interface documentation.

Signed-off-by: Timothy Chen <d7b2ae30d8c0f215facd721941273067fd1d14a2@google.com>

[flash_ctrl] Minor tweak to documentation

Signed-off-by: Timothy Chen <d7b2ae30d8c0f215facd721941273067fd1d14a2@google.com>

lowRISC/opentitan,lowRISC/opentitan,lowRISC/opentitan,lowRISC/opentitan,lowRISC/opentitan,lowRISC/opentitan