ARM: dts: msm: Update max number of images for mdm4 on fsm9900

The PIL will now load one image on mdm4 instead of eight.

Change-Id: I1cb24963549e7bf8d56de6b5fc39fd2894e271a4
Acked-by: Kaushik Sikdar <ksikdar@qti.qualcomm.com>
Signed-off-by: Venkatesh Yadav Abbarapu <quicvenkat@codeaurora.org>