MAINTAINERS: Update section for cpuidle-psci

Add myself as a co-maintainer for the cpuidle-psci driver and the
corresponding git-tree, which I am already using for this.

Cc: Lorenzo Pieralisi <lpieralisi@kernel.org>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Sudeep Holla <sudeep.holla@arm.com>
Link: https://lore.kernel.org/r/20250217140145.117086-1-ulf.hansson@linaro.org

Author: Ulf Hansson

MAINTAINERS

@@ -6087,9 +6087,11 @@ F:	include/linux/platform_data/cpuidle-exynos.h
 CPUIDLE DRIVER - ARM PSCI
 M:	Lorenzo Pieralisi <lpieralisi@kernel.org>
 M:	Sudeep Holla <sudeep.holla@arm.com>
+M:	Ulf Hansson <ulf.hansson@linaro.org>
 L:	linux-pm@vger.kernel.org
 L:	linux-arm-kernel@lists.infradead.org (moderated for non-subscribers)
 S:	Supported
+T:	git git://git.kernel.org/pub/scm/linux/kernel/git/ulfh/linux-pm.git
 F:	drivers/cpuidle/cpuidle-psci.c
 
 CPUIDLE DRIVER - ARM PSCI PM DOMAIN