msm_fb: display: Evenly balancing load on MDP ports

Moving RGB1 and RGB2 to AXI port 1. This fixes underrun issues seen
on External display while connecting and disconnecting HDMI. This patch
evenly balancing pipe loads on each port.

Change-Id: I2dc1166d04bb938f9e233a6de52f1a8a3fdd29e2
CRs-Fixed: 435458
Signed-off-by: Siddhartha Agrawal <agrawals@codeaurora.org>