powercap: intel_rapl: Use shifts for power-of-2 operations

powercap: intel_rapl: Use shifts for power-of-2 operations

Replace division by (1 << value) with shift operations for clarity and
consistency. Add ULL suffix to avoid undefined behavior from shifting
signed integers.

No functional changes intended.

Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Link: https://patch.msgid.link/20260212233044.329790-6-sathyanarayanan.kuppuswamy@linux.intel.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>