A set of fixes for interrupt chip drivers:

  - Unbreak the PLIC driver for Allwinner D1 systems

    The recent conversion of the PLIC driver to a platform driver broke
    Allwinnder D1 systems due to the deferred probing of platform drivers.

    Due to that the only timer available on D1 systems cannot get an
    interrupt, which causes the system to hang at boot. Other RISCV
    platforms are not affected because they provide the architected SBI
    timer which uses the built in core interrupt controller.

    Cure this by probing PLIC early on D1 systems

  - Cure a regression in ARM/GIC-V3 on 32-bit ARM systems caused by the
    recent addition of a initialization function, which accesses system
    registers before they are enabled. On 64-bit ARM they are enabled
    prior to that by sheer luck.

    Ensure they are enabled.

  - Cure a use before check problem in the MSI library. The existing NULL
    pointer check is too late.

  - Cure a lock order inversion in the ARM/GIC-V4 driver

  - Fix a IS_ERR() vs. NULL pointer check issue in the RISCV APLIC driver

  - Plug a reference count leak in the ARM/GIC-V2 driver