Use void pointers for untyped memory

Use void pointers for untyped memory

To avoid unnecessary casts, we can use untyped pointers when accessing
individual records.

Change-Id: I1d628d6e25f1e53b4fee34e7c2c4688a789c45a3
Signed-off-by: Philip Prindeville <philipp@redfish-solutions.com>
Reviewed-on: http://review.coreboot.org/498
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <patrick@georgi-clan.de>