phy_common: add method to check whether we use default LTE symbol size

helpful getter to check whether we've compiled in
or selected at run time to use default LTE sample rates

lib/include/srslte/phy/common/phy_common.h

@@ -444,6 +444,8 @@ SRSLTE_API int srslte_sampling_freq_hz(uint32_t nof_prb);
 
 SRSLTE_API void srslte_use_standard_symbol_size(bool enabled);
 
+SRSLTE_API bool srslte_symbol_size_is_standard();
+
 SRSLTE_API uint32_t srslte_re_x_prb(uint32_t ns, uint32_t symbol, uint32_t nof_ports, uint32_t nof_symbols);
 
 SRSLTE_API uint32_t srslte_voffset(uint32_t symbol_id, uint32_t cell_id, uint32_t nof_ports);

lib/src/phy/common/phy_common.c

@@ -321,6 +321,11 @@ void srslte_use_standard_symbol_size(bool enabled)
   use_standard_rates = enabled;
 }
 
+bool srslte_symbol_size_is_standard()
+{
+  return use_standard_rates;
+}
+
 int srslte_sampling_freq_hz(uint32_t nof_prb)
 {
   int n = srslte_symbol_sz(nof_prb);