default or selected kernelversion does not have config value CONFIG_ARCH_USES_PG_ARCH_X.
Result is shown for kernelversion 6.9.9

CONFIG_ARCH_USES_PG_ARCH_X (not configurable)

configname: CONFIG_ARCH_USES_PG_ARCH_X

Linux Kernel Configuration
└─>Memory Management options
└─>ARCH_USES_PG_ARCH_X
In linux kernel since version 6.2 (release Date: 2023-02-19)  
Enable the definition of PG_arch_x page flags with x > 1. Only
suitable for 64-bit architectures with CONFIG_FLATMEM or
CONFIG_SPARSEMEM_VMEMMAP enabled, otherwise there may not be
enough room for additional bits in page->flags.