accel/ivpu/40xx: Fix missing VPUIP interrupts

Move sequence of masking and unmasking global interrupts from buttress
interrupt handler to generic one that handles both VPUIP and BTRS
interrupts.

Unmasking global interrupts will re-trigger MSI for any pending interrupts.
Lack of this sequence can randomly cause to miss any VPUIP interrupt that
comes after reading VPU_40XX_HOST_SS_ICB_STATUS_0 and before clearing
all active interrupt sources.

Fixes: 79cdc56c ("accel/ivpu: Add initial support for VPU 4")
Signed-off-by: Karol Wachowski <karol.wachowski@linux.intel.com>
Reviewed-by: Stanislaw Gruszka <stanislaw.gruszka@linux.intel.com>
Reviewed-by: Jeffrey Hugo <quic_jhugo@quicinc.com>
Signed-off-by: Stanislaw Gruszka <stanislaw.gruszka@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230925121137.872158-6-stanislaw.gruszka@linux.intel.com