Update daisy_patch_sm.cpp (#630)

Removed redundant internal DAC buffer.

Increases DAC range by around 0.4 Volts 
Allows for the full 0.0v - 3.3v range.

"With internal buffer on, the min DAC_OUT is 0.2V and max DAC_OUT is VDDA-0.2V"

Page 163
https://www.st.com/resource/en/datasheet/stm32h750ib.pdf

Author: IC-Alchemy

src/daisy_patch_sm.cpp

@@ -181,7 +181,7 @@ namespace patch_sm
         dac_config.bitdepth = DacHandle::BitDepth::
             BITS_12; /**< Sets the output value to 0-4095 */
         dac_config.chn               = DacHandle::Channel::BOTH;
-        dac_config.buff_state        = DacHandle::BufferState::ENABLED;
+        dac_config.buff_state        = DacHandle::BufferState::DISABLED;    //  Internal buffer disabled on Patch_SM
         dac_config.target_samplerate = 48000;
         dac_.Init(dac_config);
     }
@@ -535,4 +535,4 @@ namespace patch_sm
 
 } // namespace patch_sm
 
-} // namespace daisy
+} // namespace daisy