x86/idle: Change arguments of mwait_idle_with_hints() to u32

All functions in mwait_idle_with_hints() cast eax and ecx arguments
to u32. Propagate argument type to the enclosing function.

Suggested-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20250403073105.245987-1-ubizjak@gmail.com