NOUPSTREAM: ANDROID: pcie/dwc: driver: export dw_handle_msi_irq

Needed for vendors' pcie stack.

[CPNOTE: 06/07/21] Lee: Vendor GKI code

Bug: 165922442
Signed-off-by: David Hongseock Kim <hongpooh.kim@samsung.com>
Change-Id: I900b5a55b174819573c2f8eedcefae73aee7b6a7
Signed-off-by: Mark Salyzyn <salyzyn@google.com>
Signed-off-by: Will McVicker <willmcvicker@google.com>
Signed-off-by: Lee Jones <joneslee@google.com>