travis: Break up the NXP Layerscape jobs more

The single job for all Layerscape 10xx platforms is close to, and
sometimes exceeds the time limit for a single job configuration.  Break
this down into jobs for LS101x, LS104x and LS108x instead.  While in
here, in the name portion of these jobs, refer to them as NXP for ARM
and not Freescale as they've been NXP for quite some time.

Signed-off-by: Tom Rini <trini@konsulko.com>