msm: devices: Separate and correct 8064 footswitch device list

8064 does not have GFX2D cores as 8960 did, so do not try to probe those
footswitch devices. Do, however, probe the new VCAP core that was not
present on 8960.

The MDP footswitch device on 8064 is temporarily omitted from the table
until stability issues with its integration with the display driver are
resolved.

Change-Id: I60ceaaec1f2da1c6af0f2523c2a2f6f8134ac8bc
Signed-off-by: Matt Wagantall <mattw@codeaurora.org>