gccarmemb: don't assume 'dtc' is in /usr/bin

Just search for it in the system PATH.

Issue: ZEP-2211
Signed-off-by: Andrew Boie <[email protected]>

Author: Andrew Boie

scripts/Makefile.toolchain.gccarmemb

@@ -10,6 +10,6 @@ LIBGCC_DIR = $(shell dirname `$(CROSS_COMPILE)gcc ${KBUILD_CFLAGS} -print-libgcc
 LIB_INCLUDE_DIR += -L ${LIBGCC_DIR}
 TOOLCHAIN_CFLAGS = -I${GCCARMEMB_TOOLCHAIN_PATH}/arm-none-eabi/include
 
-DTC ?= /usr/bin/dtc
+DTC ?= dtc
 
 export CROSS_COMPILE TOOLCHAIN_LIBS TOOLCHAIN_CFLAGS LIB_INCLUDE_DIR DTC