Pull mailbox updates from Jassi Brar:
- imx: add support for i.MX8/8X to existing driver
- mediatek: drop the atomix execution feature, add flush
- allwinner: new 'msgbox' controller driver
- armada: misc: drop redundant error print
- bcm: misc: catch error in probe and snprintf buffer overflow
* tag 'mailbox-v5.7' of git://git.linaro.org/landing-teams/working/fujitsu/integration:
mailbox: imx: add SCU MU support
mailbox: imx: restructure code to make easy for new MU
dt-bindings: mailbox: imx-mu: add SCU MU support
mailbox: mediatek: remove implementation related to atomic_exec
mailbox: mediatek: implement flush function
dt-binding: gce: remove atomic_exec in mboxes property
maillbox: bcm-flexrm-mailbox: handle cmpl_pool dma allocation failure
mailbox: sun6i-msgbox: Add a new mailbox driver
dt-bindings: mailbox: Add a binding for the sun6i msgbox
mailbox: bcm-pdc: Use scnprintf() for avoiding potential buffer overflow
mailbox:armada-37xx-rwtm:remove duplicate print in armada_37xx_mbox_probe()