drm/msm/dpu: Factor out shared interrupt register in INTF_BLK macro

As the INTF block is going to attain more interrupts that don't share
the same MDP_SSPP_TOP0_INTR register, factor out the _reg argument for
the caller to construct the right interrupt index (register and bit
index) to not make the interrupt bit arguments depend on one of multiple
interrupt register indices.  This brings us more in line with how PP_BLK
specifies its interrupts and allows for better wrapping in the arrays.

Signed-off-by: Marijn Suijten <marijn.suijten@somainline.org>
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Patchwork: https://patchwork.freedesktop.org/patch/534222/
Link: https://lore.kernel.org/r/20230411-dpu-intf-te-v4-17-27ce1a5ab5c6@somainline.org


Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>