PM: sleep: Clean up MAINTAINERS entries for suspend and hibernation

Since Pavel Machek and Len Brown do not actually maintain the system
suspend and hibernation code, change their records in the relevant
MAINTAINERS entries to reviewers.

While at it, use Len Brown's kernel.org address in the suspend-to-RAM
MAINTAINERS record.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://patch.msgid.link/2798682.mvXUDI8C0e@rjwysocki.net
Link: https://lore.kernel.org/linux-pm/20250313091403.50077-1-krzysztof.kozlowski@linaro.org/


[ rjw: Add a Link tag relevant to this change, edit changelog ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>