[llvm] [libsycl] Generic code cleanup (PR #224330)

[Kseniya Tikhomirova via llvm-commits]

================
@@ -49,59 +51,59 @@ SelectDevice(const DeviceSelectorInvocableType &DeviceSelector);
 /// Standard device selector to select SYCL device from any supported SYCL
 /// backend based on an implementation-defined heuristic.
 ///
-/// \param Dev device to calculate the score for.
+/// \param dev device to calculate the score for.
----------------
KseniyaTikhomirova wrote:

we have libsycl coding standard extension to LLVM coding standards saying that we align API names with SYCL 2020 spec and the rest follows LLVM guidelines https://github.com/llvm/llvm-project/blob/main/libsycl/docs/CodingGuidelines.md#names-of-macros-types-functions-variables-and-enumerators.

I consider this as a relatively good thing from the point of view that generated Doxygen documentation will have names that will be easily mapped to SYCL 2020 specification since names in libsycl doc and in spec will be completely identical. 

https://github.com/llvm/llvm-project/pull/224330