lib: sbi: Simplify ipi platform operations

Instead of having ipi_send() and ipi_clear() callbacks in
platform operations, it will be much simpler for ipi driver
to directly register these operations as a device to sbi_ipi
implementation.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>

platform/fpga/openpiton/platform.c

@@ -182,8 +182,6 @@ const struct sbi_platform_operations platform_ops = {
 	.console_init = openpiton_console_init,
 	.irqchip_init = openpiton_irqchip_init,
 	.ipi_init = openpiton_ipi_init,
-	.ipi_send = clint_ipi_send,
-	.ipi_clear = clint_ipi_clear,
 	.timer_init = openpiton_timer_init,
 };