package/gdb: enable gdbserver support for riscv

It turn out that gdbserver support for riscv is available since 10.1 release, since commit [1].

Restrict the gdb version choice for riscv to 10.1 for simplicity [2].

[1] https://sourceware.org/git/?p=binutils-gdb.git;a=commitdiff;h=bf84f7066626c78884436e1c39fb60f04c665f21
[2] http://lists.busybox.net/pipermail/buildroot/2021-June/312681.html

Signed-off-by: Romain Naour <romain.naour@gmail.com>
Cc: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
Cc: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

package/gdb/Config.in

@@ -19,8 +19,6 @@ config BR2_PACKAGE_GDB
 	depends on BR2_PACKAGE_GDB_ARCH_SUPPORTS
 	depends on BR2_TOOLCHAIN_GCC_AT_LEAST_4_8
 	depends on BR2_INSTALL_LIBSTDCPP
-	# no gdbserver on riscv
-	select BR2_PACKAGE_GDB_DEBUGGER if BR2_riscv
 	# When the external toolchain gdbserver is copied to the
 	# target, we don't allow building a separate gdbserver. The
 	# one from the external toolchain should be used.
@@ -47,7 +45,6 @@ if BR2_PACKAGE_GDB
 config BR2_PACKAGE_GDB_SERVER
 	bool "gdbserver"
 	depends on !BR2_TOOLCHAIN_EXTERNAL_GDB_SERVER_COPY
-	depends on !BR2_riscv
 	help
 	  Build the gdbserver stub to run on the target.
 	  A full gdb is needed to debug the progam.

package/gdb/Config.in.host

@@ -4,7 +4,6 @@ config BR2_PACKAGE_HOST_GDB_ARCH_SUPPORTS
 	depends on !((BR2_arm || BR2_armeb) && BR2_BINFMT_FLAT)
 	depends on !BR2_microblaze
 	depends on !BR2_or1k
-	depends on !BR2_riscv
 	depends on !BR2_nds32
 
 comment "Host GDB Options"
@@ -70,9 +69,13 @@ choice
 
 config BR2_GDB_VERSION_8_3
 	bool "gdb 8.3.x"
+	# gdbserver support missing
+	depends on !BR2_riscv
 
 config BR2_GDB_VERSION_9_2
 	bool "gdb 9.2.x"
+	# gdbserver support missing
+	depends on !BR2_riscv
 
 config BR2_GDB_VERSION_10
 	bool "gdb 10.x"
@@ -87,6 +90,6 @@ config BR2_GDB_VERSION
 	default "arc-2020.09-release-gdb" if BR2_arc
 	default "4ecb98fbc2f94dbe01b69384afbc515107de73df" if BR2_csky
 	default "8.3.1"    if BR2_GDB_VERSION_8_3
-	default "9.2"      if BR2_GDB_VERSION_9_2 || !BR2_PACKAGE_HOST_GDB
-	default "10.1"	   if BR2_GDB_VERSION_10
+	default "9.2"      if BR2_GDB_VERSION_9_2 || (!BR2_PACKAGE_HOST_GDB && !BR2_riscv)
+	default "10.1"	   if BR2_GDB_VERSION_10 || (!BR2_PACKAGE_HOST_GDB && BR2_riscv)
 	depends on BR2_PACKAGE_GDB || BR2_PACKAGE_HOST_GDB