Revert "Added Support for 64bit RGB format"

Revert "Added Support for 64bit RGB format"
This reverts commit 47bd806579dd
The Android framework uses successful allocation of
HAL_PIXEL_FORMAT_RGBA_FP16 to test for wide-gamut capabilities.
We don't want to advertise this, so let's revert.

This revert won't cause regression on CTS test case
android.hardware.cts.HardwareBufferTest#testCreate

android.graphics.cts.BitmapColorSpaceTest#test16bitHardware
can pass if the framework falls back to RGBA8888, as is the plan.

Jira: https://jira01.devtools.intel.com/browse/OAM-68897
Tests: test16bitHardware and testCreate both pass