devel: gcc: add missing RISCV patches for GCC 12

Add missing RISCV patches for GCC 12 from openwrt toolchain GCC.

Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>

devel/gcc/patches-12.x/701-riscv-linux-Don-t-add-latomic-with-pthread.patch

@@ -0,0 +1,36 @@
+From 203f3060dd363361b172f7295f42bb6bf5ac0b3b Mon Sep 17 00:00:00 2001
+From: Andreas Schwab <schwab@suse.de>
+Date: Sat, 23 Apr 2022 15:48:42 +0200
+Subject: [PATCH] riscv/linux: Don't add -latomic with -pthread
+
+Now that we have support for inline subword atomic operations, it is no
+longer necessary to link against libatomic.  This also fixes testsuite
+failures because the framework does not properly set up the linker flags
+for finding libatomic.
+The use of atomic operations is also independent of the use of libpthread.
+
+gcc/
+	* config/riscv/linux.h (LIB_SPEC): Don't redefine.
+---
+ gcc/config/riscv/linux.h | 10 ----------
+ 1 file changed, 10 deletions(-)
+
+--- a/gcc/config/riscv/linux.h
++++ b/gcc/config/riscv/linux.h
+@@ -35,16 +35,6 @@ along with GCC; see the file COPYING3.
+ #undef MUSL_DYNAMIC_LINKER
+ #define MUSL_DYNAMIC_LINKER "/lib/ld-musl-riscv" XLEN_SPEC MUSL_ABI_SUFFIX ".so.1"
+ 
+-/* Because RISC-V only has word-sized atomics, it requries libatomic where
+-   others do not.  So link libatomic by default, as needed.  */
+-#undef LIB_SPEC
+-#ifdef LD_AS_NEEDED_OPTION
+-#define LIB_SPEC GNU_USER_TARGET_LIB_SPEC \
+-  " %{pthread:" LD_AS_NEEDED_OPTION " -latomic " LD_NO_AS_NEEDED_OPTION "}"
+-#else
+-#define LIB_SPEC GNU_USER_TARGET_LIB_SPEC " -latomic "
+-#endif
+-
+ #define ICACHE_FLUSH_FUNC "__riscv_flush_icache"
+ 
+ #define CPP_SPEC "%{pthread:-D_REENTRANT}"