default or selected kernelversion does not have config value CONFIG_MTD_NAND_H1900.
Result is shown for kernelversion 6.2.5

iPAQ H1900 flash

modulename: h1910.ko

configname: CONFIG_MTD_NAND_H1900

Linux Kernel Configuration
└─>Device Drivers
└─>Memory Technology Device (MTD) support
└─>NAND Device Support
└─>iPAQ H1900 flash
In linux kernel since version 2.6.20 (release Date: 2007-02-04)  
This enables the driver for the iPAQ h1900 flash.

source code:
drivers/mtd/nand//h1910.c