CONFIG_ARCH_NXP is not available for the selected architecture x86.
Result is shown for architecture arm64

NXP SoC support

configname: CONFIG_ARCH_NXP

Linux Kernel Configuration
└─>Platform selection
└─>NXP SoC support
In linux kernel since version 4.14.326 (release Date: 2023-09-23)
is selected by
CONFIG_ARCH_LAYERSCAPE