MSI functions for allocation and free can be directly used by
the device drivers without any wrapper provided by bus drivers.
So export these MSI functions.

Also, add a wrapper API to allocate MSIs providing only the
number of interrupts rather than range for simpler driver usage.
Signed-off-by: Nipun Gupta <nipun.gupta@amd.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20240423111021.1686144-1-nipun.gupta@amd.comSigned-off-by: Alex Williamson <alex.williamson@redhat.com>