ARM: dts: msm: Disable RB sampler optimization

Disable RB sampler data path optimization for
for 1-SP A5xx GPU's. Right now we have A505
and A506 with one 1-SP GPU's and same is to be
done for future targets with 1-SP.

Change-Id: I99e88f8ef70d7599dfba1b9e419ac6984f60c656
Signed-off-by: Sunil Khatri <sunilkh@codeaurora.org>