ARM: davinci: aintc: use a common prefix for symbols in the driver

In preparation for moving the driver to drivers/irqchip do some
cleanup: use a common prefix for all symbols.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Reviewed-by: David Lechner <david@lechnology.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>