sparc64: Deselect IRQ_PREFLOW_FASTEOI

sparc64 hasn't needed to select this since commit:

  ee6a9333 ("sparc64: sparse irq")

which got rid of the calls to __irq_set_preflow_handler() first installed
by commit:

  fcd8d4f4 ("sparc: Use the new genirq functionality")

Deselect this option.

Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Anatoly Pugachev <matorola@gmail.com>
Link: https://lkml.kernel.org/r/20200703155645.29703-2-valentin.schneider@arm.com