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 will cause the driver to miss any
VPUIP interrupt that comes after reading VPU_37XX_HOST_SS_ICB_STATUS_0
and before clearing all active interrupt sources.

Fixes: 35b13763 ("accel/ivpu: Introduce a new DRM driver for Intel VPU")
Cc: stable@vger.kernel.org
Signed-off-by: Karol Wachowski <karol.wachowski@linux.intel.com>
Reviewed-by: Stanislaw Gruszka <stanislaw.gruszka@linux.intel.com>
Signed-off-by: Stanislaw Gruszka <stanislaw.gruszka@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231024161952.759914-1-stanislaw.gruszka@linux.intel.com