powerpc: Restore some misc devices to our configs

Uwe Kleine-König reported:

	while working on an defconfig (arm/mx27) I noticed that just updating
	it[1] results in removing CONFIG_EEPROM_AT24=y.  The reason is that
	since commit

		v2.6.36-5965-g5f2365d (misc devices: do not enable by default)

	MISC_DEVICES isn't enabled anymore by default.  So all defconfigs that
	have CONFIG_SOME_SYMBOL=y (or =m) (with SOME_SYMBOL depending on
	MISC_DEVICES) but not CONFIG_MISC_DEVICES=y suffer from the same
	problem.

This restores those misc devices to the powerpc defconfigs.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Uwe Kleine-König <u.kleine-koenig@pengutronix.de
Acked-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>
Acked-by: Uwe Kleine-König
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>