Enable LSI interrupt after masking sources in interrupt service init
Enable LSI interrupt after masking sources in interrupt service init

In DD2 the interrupt HW is initialized in a different state to make
things safer. The idea is to prevent hot interrupts from firing
when we are not ready.

Change-Id: Ie31ad1f8f2dc0e5ba5bf62118f0ade8ed8097790
Reviewed-on: http://ralgit01.raleigh.ibm.com/gerrit1/42053
Tested-by: Jenkins Server <8e3f934e4c44875bc48d33da3ea13d93ba9a233f@us.ibm.com>
Tested-by: Jenkins OP Build CI <e610bd72261d3c0a48f1e8ae36832ab00774d426@us.ibm.com>
Tested-by: FSP CI Jenkins <aa9e4d9ac7cd25905e9c0dd36d4150516e73dd86@us.ibm.com>
Reviewed-by: Dean Sanner <3b8f978f111a0718dcf88848e092ac780da17ab3@us.ibm.com>
Reviewed-by: Sachin Gupta <285b19a698aa558fba6ab25cf25b393d072fd749@in.ibm.com>
Reviewed-by: Daniel M. Crowell <912029ca9254ac7b5854e56910561d682e1fa2d0@us.ibm.com>

open-power/hostboot,open-power/hostboot,open-power/hostboot,open-power/hostboot,open-power/hostboot