Improve the refresh rate precision. (AMDVLK #268)

[qiaojbao]

No description provided.

[amdvlk-admin]

6b7e722 Jenkins build error.
/jenkins/workspace/vulkan/sanitized-opensource/Github-PR/pal-github-pr/driver_build/drivers/xgl/icd/api/vk_physical_device.cpp:9477:76: error: no match for ‘operator*’ (operand types are ‘Pal::Rational’ {aka ‘Util::Rational’} and ‘int’)
9477 | properties[i].parameters.refreshRate = pScreenMode[i]->refreshRate * 1000;
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~ ^ ~~~~
| | |
| | int
| Pal::Rational {aka Util::Rational}

/jenkins/workspace/vulkan/sanitized-opensource/Github-PR/pal-github-pr/driver_build/drivers/xgl/icd/api/vk_physical_device.cpp:9541:90: error: no match for ‘operator*’ (operand types are ‘Pal::Rational’ {aka ‘Util::Rational’} and ‘int’)
9541 | (pCreateInfo->parameters.refreshRate == pScreenMode[i]->refreshRate * 1000))
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~ ^ ~~~~
| | |
| | int
| Pal::Rational {aka Util::Rational}
/jenkins/workspace/vulkan/sanitized-opensource/Github-PR/pal-github-pr/driver_build/drivers/xgl/icd/api/vk_physical_device.cpp:9572:77: error: no match for ‘operator=’ (operand types are ‘Pal::Rational’ {aka ‘Util::Rational’} and ‘const uint32_t’ {aka ‘const unsigned int’})
9572 | pNewMode->palScreenMode.refreshRate = pCreateInfo->parameters.refreshRate;
| ^~~~~~~~~~~
In file included from /jenkins/workspace/vulkan/sanitized-opensource/Github-PR/pal-github-pr/driver_build/drivers/pal/inc/core/./palFormat.h:34,
from /jenkins/workspace/vulkan/sanitized-opensource/Github-PR/pal-github-pr/driver_build/drivers/pal/inc/core/./pal.h:34,
from /jenkins/workspace/vulkan/sanitized-opensource/Github-PR/pal-github-pr/driver_build/drivers/pal/inc/core/./palPlatform.h:34,