Migrate grc blocks from xml to yaml

Convert the blocks using cmdline_converter.py script from
https://gist.githubusercontent.com/haakov/4228ff6a14486641add538483093e86b/raw/c861a840e31182ace2e74f5425e356cb4f8b183a/cmdline_converter.py

Change-Id: Iee5c611a2e100bd2fdf487611a867dc937d8c292
diff --git a/grc/demapping/gsm_tch_f_chans_demapper.block.yml b/grc/demapping/gsm_tch_f_chans_demapper.block.yml
new file mode 100644
index 0000000..8d10c1d
--- /dev/null
+++ b/grc/demapping/gsm_tch_f_chans_demapper.block.yml
@@ -0,0 +1,30 @@
+# auto-generated by grc.converter
+
+id: gsm_tch_f_chans_demapper
+label: TCH/F Demapper
+
+parameters:
+-   id: timeslot_nr
+    label: Timeslot
+    dtype: int
+    default: '2'
+    hide: part
+
+inputs:
+-   domain: message
+    id: bursts
+    optional: true
+
+outputs:
+-   domain: message
+    id: tch_bursts
+    optional: true
+-   domain: message
+    id: acch_bursts
+    optional: true
+
+templates:
+    imports: import grgsm
+    make: grgsm.tch_f_chans_demapper(${timeslot_nr})
+
+file_format: 1