add libjson-c-dev dependency (for litex)

diff --git a/install-hdl-apt-reqs b/install-hdl-apt-reqs
index 2fca663b9945f2c34ae197d855c862cf36725c23..f554d8684c190168c830bcc84f09ff44dacdd05a 100755 (executable)
--- a/install-hdl-apt-reqs
+++ b/install-hdl-apt-reqs
@@ -22,6 +22,7 @@ apt-get install -y autoconf \
     iverilog \
     libboost-program-options-dev \
     libffi-dev \
+    libjson-c-dev \
     libftdi-dev \
     libgmp-dev \
     libmpfr-dev \