irqchip: gicv3-its: Move some alloc/free code to activate/deactivate
irqchip: gicv3-its: Move some alloc/free code to activate/deactivate

The ITS code could do a bit less in the alloc/free paths, and a bit
more in the activate/deactivate methods, giving a better separation
between software allocation and HW programing.

Suggested-by: Wuyun Wu (Abel) <5a192a0fd705103476017f53b6e2a3294204b2bb@huawei.com>
Signed-off-by: Marc Zyngier <a16cc0c82647c52d401177f8e50567df5499e36c@arm.com>
Cc: f99ef57ccac738b558d0fc2e44478b3c5def9522@lists.infradead.org
Cc: Yun Wu (Abel) <5a192a0fd705103476017f53b6e2a3294204b2bb@huawei.com>
Cc: Robert Richter <22a70fd9773e4de05b12c05075e9bcd605577f4d@caviumnetworks.com>
Cc: Jason Cooper <68c46a606457643eab92053c1c05574abb26f861@lakedaemon.net>
Signed-off-by: Thomas Gleixner <00e4cf8f46a57000a44449bf9dd8cbbcc209fd2a@linutronix.de>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs