c6x: Replace setup_irq() by request_irq()

c6x: Replace setup_irq() by request_irq()

request_irq() is preferred over setup_irq(). Invocations of setup_irq()
occur after memory allocators are ready.

setup_irq() was required in older kernels as the memory allocator was not
available during early boot.

Hence replace setup_irq() by request_irq().

Signed-off-by: afzal mohammed <afzal.mohd.ma@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/56e991e920ce5806771fab892574cba89a3d413f.1585320721.git.afzal.mohd.ma@gmail.com