dt-bindings: iommu: renesas, ipmmu-vmsa: Update for R-Car Gen4

Since R-Car Gen4 does not have the main IPMMU IMSSTR register, update
the bindings to drop the interrupt bit number from the
renesas,ipmmu-main property.

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
[geert: Re-add removed items level, add minItems/maxItems constraints]
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20230313124026.954514-1-yoshihiro.shimoda.uh@renesas.com


Signed-off-by: Joerg Roedel <jroedel@suse.de>