Support setting the samd charge rate

We default to the fast one, and do not try setting the charge rate bit
on older samd versions

src/drivers/include/drivers/samd.hpp

@@ -56,6 +56,7 @@ class Samd {
   auto UpdateUsbStatus() -> void;
 
   auto ResetToFlashSamd() -> void;
+  auto SetFastChargeEnabled(bool) -> void;
   auto PowerDown() -> void;
 
   auto UsbMassStorage(bool en) -> void;

src/drivers/samd.cpp

@@ -51,6 +51,7 @@ Samd::Samd() {
 
   UpdateChargeStatus();
   UpdateUsbStatus();
+  SetFastChargeEnabled(true);
 }
 Samd::~Samd() {}
 
@@ -125,6 +126,18 @@ auto Samd::ResetToFlashSamd() -> void {
   ESP_ERROR_CHECK(transaction.Execute(3));
 }
 
+auto Samd::SetFastChargeEnabled(bool en) -> void {
+  if (version_ < 4) {
+    return;
+  }
+  I2CTransaction transaction;
+  transaction.start()
+      .write_addr(kAddress, I2C_MASTER_WRITE)
+      .write_ack(Registers::kPowerControl, (en << 1))
+      .stop();
+  ESP_ERROR_CHECK(transaction.Execute(3));
+}
+
 auto Samd::PowerDown() -> void {
   I2CTransaction transaction;
   transaction.start()