Here's an ABC file of something approaching it:

X:1
T:Galway Girl
M:4/4
L:1/8
Q:120
C:Steve Earle
K:D
DE| F2(3EFE D2 DE | F2F2FED A | B2B2Bcdc | B2A2A2 FA | B2B2A2 F2 |GFG2F2D2|
E2E2EFGF | E2D2D2A2 | B3AB3AB2 | c2 d2 B2 A2 | ABAG F2 E4-|E2
A2B2B2 | A2F2GAG2 | F2 D2E2 ED | EFGFE2D2 | D4 :|

Go to this site and paste it into the box and submit - it should produce a midi file and a PDF of the notes.

I have a mandolin tab for it too if you want one but would need somewhere to send it to - it's pretty easy to figure though as it's all on the D and A strings and Open, 2,4 and 5!

Hope it's the right thing. There are more twiddles in what he plays on the whistle but it's not far off the basics