SYCL: Add support for FLOOR,CEIL,ROUND and TRUNC unary operators (#16613)

SYCL: Add support for FLOOR,CEIL,ROUND and TRUNC unary operators (#16613)

* SYCL: Add support for FLOOR,CEIL,ROUND and TRUNC unary operators

Clean up unrelated changes from previous commit

* Chore: remove empty lines and fix indentation

* Clean up: remove leftover blank lines and fix spacing

* chore: fix trailing whitespace and ensure final newline

* Cleanup: remove redundant declarations already defined in header

* Sync docs/ops.md with updated backend operation support

* docs: update ops.md after rebase

* docs: update ops.md - Vulkan supports SSM_CONV and SSM_SCAN