edge: Add numDataHeaderBitsUL/DL and numDataBlockHeaderBits methods

These methods are added to GprsCodingScheme to avoid related
switch statements in the RLC block encoder for EGPRS.

Sponsored-by: On-Waves ehf
diff --git a/src/gprs_coding_scheme.h b/src/gprs_coding_scheme.h
index 854deb6..348aefb 100644
--- a/src/gprs_coding_scheme.h
+++ b/src/gprs_coding_scheme.h
@@ -47,6 +47,7 @@
 		HEADER_EGPRS_DATA_TYPE_1,
 		HEADER_EGPRS_DATA_TYPE_2,
 		HEADER_EGPRS_DATA_TYPE_3,
+		NUM_HEADER_TYPES
 	};
 
 	GprsCodingScheme(Scheme s = UNKNOWN);
@@ -80,6 +81,9 @@
 	unsigned int spareBitsDL() const;
 	unsigned int maxDataBlockBytes() const;
 	unsigned int numDataBlocks() const;
+	unsigned int numDataHeaderBitsUL() const;
+	unsigned int numDataHeaderBitsDL() const;
+	unsigned int numDataBlockHeaderBits() const;
 	const char *name() const;
 	HeaderType headerTypeData() const;
 	HeaderType headerTypeControl() const;