fix correctly rounded behavior for math bruteforce tests

[bashbaug]

fixes #2387

Corrects the "correctly rounded" behavior for the math bruteforce tests. Specifically:

• Only applies the -cl-fp32-correctly-rounded-divide-sqrt build option for the divide_cr and sqrt_cr tests. The other tests do not receive this build option. This means that there is a difference in the behavior of the divide and divide_cr tests and the sqrt and sqrt_cr tests, and the "correctly rounded" build option is not applied to the fp16 or fp64 tests.
• Removes the build option to toggle testing the correctly rounded divide and square root tests since it no longer needed. Instead, the test names can be used to choose whether to test the correctly rounded functions or the non-correctly rounded functions.

Additionally:

• Relaxes the fp16 sqrt accuracy requirements to 1 ULP. This is needed to pass this test on some of our devices. This part is still under discussion, so I will keep this PR as a draft until it is settled.

[bashbaug]

Related spec change: KhronosGroup/OpenCL-Docs#1386