default or selected kernelversion does not have config value CONFIG_RISCV_RPMI_SYSMSI.
Result is shown for kernelversion 6.18-rc3

CONFIG_RISCV_RPMI_SYSMSI (not configurable)

modulename: irq-riscv-rpmi-sysmsi.ko

configname: CONFIG_RISCV_RPMI_SYSMSI

Linux Kernel Configuration
└─>Device Drivers
└─>IRQ chip support
└─>Mailbox Hardware Support
└─>RISCV_RPMI_SYSMSI
source code:
selects
CONFIG_IRQ_DOMAIN_HIERARCHY
CONFIG_GENERIC_MSI_IRQ