Previously the CPU driver had a dependency on the GIC driver.
But by design is should be the opposite. The CPU driver installs the
CPU protocol that exposes the exception registration function.
And then, the interrupt controller registers its IRQ handler through
this interface.
git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@11860 6f19259b-4bc3-4df7-8a09-765794883524