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/transmitter/gsm_gmsk_mod.block.yml b/grc/transmitter/gsm_gmsk_mod.block.yml
new file mode 100644
index 0000000..e45e303
--- /dev/null
+++ b/grc/transmitter/gsm_gmsk_mod.block.yml
@@ -0,0 +1,49 @@
+# auto-generated by grc.converter
+
+id: gsm_gmsk_mod
+label: GMSK Modulator for GSM
+
+parameters:
+-   id: BT
+    label: 3 dB Time-Bandwidth Product
+    dtype: raw
+    default: '4'
+-   id: pulse_duration
+    label: Pulse Duration
+    dtype: raw
+    default: '4'
+-   id: sps
+    label: Samples/Symbol
+    dtype: raw
+    default: '4'
+
+inputs:
+-   domain: stream
+    dtype: byte
+    vlen: 1
+    optional: true
+
+outputs:
+-   domain: stream
+    dtype: complex
+    vlen: 1
+    optional: true
+
+templates:
+    imports: from grgsm import gsm_gmsk_mod
+    make: |-
+        gsm_gmsk_mod(
+            BT=${BT},
+            pulse_duration=${pulse_duration},
+            sps=${sps},
+        )
+    callbacks:
+    - set_BT(${BT})
+    - set_pulse_duration(${pulse_duration})
+    - set_sps(${sps})
+
+documentation: |-
+    Piotr Krysik
+    GMSK Modulator for GSM
+
+file_format: 1