ARM: dts: msm: Avoid conflict in I2C nodes for sdxpoorwills

Fix issue where I2C nodes were being overwritten
due to redefinition. Aliases do not define new
nodes, these are defined by the node name only.
Rename the I2C nodes with alternate pin configuration
as "i2cb".

Change-Id: I2695f337a478f1b8343bb8337b78a731cdad1cbc
Signed-off-by: Gustavo Solaira <gustavos@codeaurora.org>