lib: sbi: Simplify system reset platform operations

Instead of having system_reset_check() and system_reset() callbacks
in platform operations, it will be much simpler for reset driver to
directly register these operations as a device to the sbi_system
implementation.

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

lib/utils/reset/fdt_reset_sifive.c

@@ -33,6 +33,4 @@ static const struct fdt_match sifive_test_reset_match[] = {
 struct fdt_reset fdt_reset_sifive = {
 	.match_table = sifive_test_reset_match,
 	.init = sifive_test_reset_init,
-	.system_reset_check = sifive_test_system_reset_check,
-	.system_reset = sifive_test_system_reset
 };