irq/platform-msi: Fix comment about maximal MSIs

Commit aff5e06b ("irq/platform-MSI: Increase the maximum MSIs the MSI
framework can support") increased the maximum MSIs to 2048.

Fix the comment to reflect that.

Signed-off-by: Matthias Brugger <mbrugger@suse.com>
Cc: gregkh@linuxfoundation.org
Cc: majun258@huawei.com
Link: http://lkml.kernel.org/r/1484592500-15400-1-git-send-email-mbrugger@suse.com


Signed-off-by: Thomas Gleixner <tglx@linutronix.de>