default or selected kernelversion does not have config value CONFIG_AGP_HP_ZX1.
Result is shown for kernelversion 6.9.9

HP ZX1 chipset AGP support

modulename: hp-agp.ko

configname: CONFIG_AGP_HP_ZX1

Linux Kernel Configuration
└─>Device Drivers
└─>Graphics support
└─>/dev/agpgart (AGP Support)
└─>HP ZX1 chipset AGP support
In linux kernel since version 2.6.20 (release Date: 2007-02-04)  
This option gives you AGP GART support for the HP ZX1 chipset
for IA64 processors.

source code: