CONFIG_MACH_E740 is not available for thedefaultarchitecture x86.
Result is shown for architecture arm

Toshiba e740

modulename: e740-pcmcia.ko

configname: CONFIG_MACH_E740

Linux Kernel Configuration
└─>PXA2xx/PXA3xx-based
└─>Intel PXA2xx/PXA3xx Implementations
└─>Toshiba e740
In linux kernel since version 2.6.25 (release Date: 2008-04-16)  
Say Y here if you intend to run this kernel on a Toshiba
e740 family PDA.

source code:
arch/arm/mach-pxa/e740-pcmcia.c