xtensa: choose the right toolchain for FDPIC by default

target/config/Config.in.binutils

@@ -8,6 +8,7 @@ default ADK_TOOLCHAIN_BINUTILS_ARC if ADK_TARGET_CPU_ARC_ARC64
 default ADK_TOOLCHAIN_BINUTILS_AVR32 if ADK_TARGET_ARCH_AVR32
 default ADK_TOOLCHAIN_BINUTILS_KVX if ADK_TARGET_ARCH_KVX
 default ADK_TOOLCHAIN_BINUTILS_NDS32 if ADK_TARGET_ARCH_NDS32
+default ADK_TOOLCHAIN_BINUTILS_XTENSA if ADK_TARGET_ARCH_XTENSA && ADK_TARGET_BINFMT_FDPIC
 default ADK_TOOLCHAIN_BINUTILS_2_26 if ADK_TARGET_ARCH_BFIN && ADK_TARGET_BINFMT_FDPIC
 default ADK_TOOLCHAIN_BINUTILS_2_43_1 if ADK_TARGET_ARCH_NIOS2
 default ADK_TOOLCHAIN_BINUTILS_2_44 if ADK_TARGET_ARCH_CRIS

target/config/Config.in.compiler

@@ -19,6 +19,7 @@ default ADK_TOOLCHAIN_GCC_KVX if ADK_TARGET_ARCH_KVX
 default ADK_TOOLCHAIN_GCC_LM32 if ADK_TARGET_ARCH_LM32
 default ADK_TOOLCHAIN_GCC_METAG if ADK_TARGET_ARCH_METAG
 default ADK_TOOLCHAIN_GCC_NDS32 if ADK_TARGET_ARCH_NDS32
+default ADK_TOOLCHAIN_GCC_XTENSA if ADK_TARGET_ARCH_XTENSA && ADK_TARGET_BINFMT_FDPIC
 default ADK_TOOLCHAIN_GCC_7 if ADK_TARGET_ARCH_C6X # ICE with newer GCC
 default ADK_TOOLCHAIN_GCC_10 if ADK_TARGET_ARCH_CRIS # no longer supported
 default ADK_TOOLCHAIN_GCC_10 if ADK_TARGET_CPU_SH_J2 # j2.patch