[configure] Fix automake version check

The configure script fails on automake-1.11 (in Fedora-11) since
it looks for 3-digit version number.

"Yann E. MORIN", added the following comment:

The check for the automake version is not against a 3-digit number,
but really against a 3-part version number, a-la 'x.y.z'. Versions
such as 1.10 and 1.11 are also valid.

 # Kernel options

 menu "Operating System"

 # Config option used throughout the config and code to determine wether

 # we have a kernel or not (there might be different bare metal stuff...

 config BARE_METAL

     bool

     default n

 config KERNEL

     string

 config KERNEL_VERSION

     string

 source config.gen/kernel.in

 endmenu