drivers: irqchip: Add sdxhedgehog registration with irqchip

Add dummy initialization for sdxhedgehog with irqchip for association
between DT compatible string and it's initialization functions.

Change-Id: I00740ad39ab8e2fa6498990389e429c1a5e8b178
Signed-off-by: Jeevan Shriram <jshriram@codeaurora.org>