tools: update V8 gypfiles for RISC-V

With the inclusion of the RISC-V 32-bit support in V8 the directory
src/heap/base/asm/riscv64 has been renamed to riscv.

PR-URL: #45149
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Richard Lau <rlau@redhat.com>
Reviewed-By: Stewart X Addison <sxa@redhat.com>
Reviewed-By: Juan José Arboleda <soyjuanarbol@gmail.com>
Reviewed-By: Jiawen Geng <technicalcute@gmail.com>

tools/v8_gypfiles/v8.gyp

@@ -1648,7 +1648,7 @@
               }],
               ['_toolset == "host" and host_arch == "riscv64" or _toolset == "target" and target_arch=="riscv64"', {
                 'sources': [
-                  '<(V8_ROOT)/src/heap/base/asm/riscv64/push_registers_asm.cc',
+                  '<(V8_ROOT)/src/heap/base/asm/riscv/push_registers_asm.cc',
                 ],
               }],
               ['_toolset == "host" and host_arch == "loong64" or _toolset == "target" and target_arch=="loong64"', {