lib: sbi_ecall: Split up sbi_ecall_replace

Split up sbi_ecall_replace so that each extension is in its individual
file.

Also reorganize the corresponding section in lib/sbi/objects.mk so
that it is grouped by extension, now that the object file targets are
split up.

Signed-off-by: Vivian Wang <dramforever@live.com>
Reviewed-by: Anup Patel <anup@brainfault.org>

lib/sbi/sbi_ecall_ipi.c

@@ -0,0 +1,36 @@
+/*
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2020 Western Digital Corporation or its affiliates.
+ *
+ * Authors:
+ *   Anup Patel <anup.patel@wdc.com>
+ *   Atish Patra <atish.patra@wdc.com>
+ */
+
+#include <sbi/sbi_error.h>
+#include <sbi/sbi_ecall.h>
+#include <sbi/sbi_ecall_interface.h>
+#include <sbi/sbi_trap.h>
+#include <sbi/sbi_ipi.h>
+
+static int sbi_ecall_ipi_handler(unsigned long extid, unsigned long funcid,
+				 const struct sbi_trap_regs *regs,
+				 unsigned long *out_val,
+				 struct sbi_trap_info *out_trap)
+{
+	int ret = 0;
+
+	if (funcid == SBI_EXT_IPI_SEND_IPI)
+		ret = sbi_ipi_send_smode(regs->a0, regs->a1);
+	else
+		ret = SBI_ENOTSUPP;
+
+	return ret;
+}
+
+struct sbi_ecall_extension ecall_ipi = {
+	.extid_start = SBI_EXT_IPI,
+	.extid_end = SBI_EXT_IPI,
+	.handle = sbi_ecall_ipi_handler,
+};