pca9554 cache reads (#5137)

esphome/components/pca9554/pca9554.h

@@ -13,6 +13,8 @@ class PCA9554Component : public Component, public i2c::I2CDevice {
 
   /// Check i2c availability and setup masks
   void setup() override;
+  /// Poll for input changes periodically
+  void loop() override;
   /// Helper function to read the value of a pin.
   bool digital_read(uint8_t pin);
   /// Helper function to write the value of a pin.
@@ -22,6 +24,8 @@ class PCA9554Component : public Component, public i2c::I2CDevice {
 
   float get_setup_priority() const override;
 
+  float get_loop_priority() const override;
+
   void dump_config() override;
 
  protected:
@@ -35,6 +39,8 @@ class PCA9554Component : public Component, public i2c::I2CDevice {
   uint8_t output_mask_{0x00};
   /// The state of the actual input pin states - 1 means HIGH, 0 means LOW
   uint8_t input_mask_{0x00};
+  /// Flags to check if read previously during this loop
+  uint8_t was_previously_read_ = {0x00};
   /// Storage for last I2C error seen
   esphome::i2c::ErrorCode last_error_;
 };