default or selected kernelversion does not have config value CONFIG_SHMOBILE_IOMMU_ADDRSIZE_64MB.
Result is shown for kernelversion 6.5.1

64 MiB

configname: CONFIG_SHMOBILE_IOMMU_ADDRSIZE_64MB

IPMMU/IPMMUI address space size
└─>64 MiB
In linux kernel since version 3.1 (release Date: 2011-10-24)