[POWERPC] Add initial support for the e300c2 core

Add support for the Freescale e300c2 core found in the MPC832x processor line.

As far as initial kernel support is concerned, the e300c2 core is
identical to the e300c1 found in the mpc834x, except that it's had its
floating point unit chopped off.

Signed-off-by: Kim Phillips <kim.phillips@freescale.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>