Pull mailbox updates from Jassi Brar:

 - arm: added mhu-v2 controller driver

 - arm_mhu_db: fix kfree by using devm_ variant

 - stm32-ipcc: misc cleanup

* tag 'mailbox-v5.11' of git://git.linaro.org/landing-teams/working/fujitsu/integration:
  mailbox: arm_mhuv2: Add driver
  dt-bindings: mailbox : arm,mhuv2: Add bindings
  mailbox: stm32-ipcc: cast void pointers to unsigned long
  mailbox: stm32-ipcc: remove duplicate error message
  mailbox: stm32-ipcc: add COMPILE_TEST dependency
  mailbox: arm_mhu_db: Fix mhu_db_shutdown by replacing kfree with devm_kfree