irqchip/riscv-imsic: Revert "Remove redundant irq_data lookups"

irqchip/riscv-imsic: Revert "Remove redundant irq_data lookups"

Commit c475c0b71314("irqchip/riscv-imsic: Remove redundant irq_data
lookups") leads to a NULL pointer deference in imsic_msi_update_msg():

 virtio_blk virtio1: 8/0/0 default/read/poll queues
 Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
 Current kworker/u32:2 pgtable: 4K pagesize, 48-bit VAs, pgdp=0x0000000081c33000
 [0000000000000000] pgd=0000000000000000, p4d=0000000000000000
 CPU: 5 UID: 0 PID: 75 Comm: kworker/u32:2 Not tainted 6.19.0-rc4-next-20260109 #1 NONE
 epc : 0x0
  ra : imsic_irq_set_affinity+0x110/0x130

The irq_data argument of imsic_irq_set_affinity() is associated with the
imsic domain and not with the top-level MSI domain. As a consequence the
code dereferences the wrong interrupt chip, which has the
irq_write_msi_msg() callback not populated.

Signed-off-by: Luo Haiyang <luo.haiyang@zte.com.cn>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Link: https://patch.msgid.link/20260113111930821RrC26avITHWSFCN0bYbgI@zte.com.cn