Since a73850bd76d0 (ARM: imx: disable IPU QoS setup for correct SoCs), which
fixed the condition to not execute the IPU QoS fixups on SoCs that don't have
a IPU, the fixups aren't applied on i.MX6Q/DP anymore, since those SoCs were
missing from the whitelist.

Add a function to make it a bit more clearer what we are checking here and add
the Q/DP SoCs.

Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>