platform: generic: Move Sifive platform overrides into own directory

Let us move SiFive platform overrides for FU540 and FU740 into a separate
directory so better maintainability. Other SoC vendors can also create
their own directory under platform/generic.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>

platform/generic/objects.mk

@@ -9,9 +9,3 @@
 
 platform-objs-y += platform.o
 platform-objs-y += platform_override_modules.o
-
-carray-platform_override_modules-y += sifive_fu540
-platform-objs-y += sifive_fu540.o
-
-carray-platform_override_modules-y += sifive_fu740
-platform-objs-y += sifive_fu740.o

platform/generic/sifive/objects.mk

@@ -0,0 +1,9 @@
+#
+# SPDX-License-Identifier: BSD-2-Clause
+#
+
+carray-platform_override_modules-y += sifive_fu540
+platform-objs-y += sifive/fu540.o
+
+carray-platform_override_modules-y += sifive_fu740
+platform-objs-y += sifive/fu740.o