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

ELSA PCMCIA MicroLink cards

modulename: elsa_cs.ko

configname: CONFIG_HISAX_ELSA_CS

Linux Kernel Configuration
└─>Device Drivers
└─>ISDN support
└─>Old ISDN4Linux (deprecated)
└─>Passive cards
└─>ELSA PCMCIA MicroLink cards
In linux kernel since version 2.6.20 (release Date: 2007-02-04)  
This enables the PCMCIA client driver for the Elsa PCMCIA MicroLink
card.

source code:
drivers/isdn/hisax/elsa_cs.c