i2c: introduce chip specific cmd register number

Merges https://github.com/espressif/esp-idf/pull/10811

components/soc/esp32c2/include/soc/Kconfig.soc_caps.in

@@ -267,6 +267,10 @@ config SOC_I2C_FIFO_LEN
     int
     default 16
 
+config SOC_I2C_CMD_REG_NUM
+    int
+    default 8
+
 config SOC_I2C_SUPPORT_HW_CLR_BUS
     bool
     default y

components/soc/esp32c2/include/soc/soc_caps.h

@@ -134,6 +134,7 @@
 #define SOC_I2C_NUM                 (1U)
 
 #define SOC_I2C_FIFO_LEN            (16) /*!< I2C hardware FIFO depth */
+#define SOC_I2C_CMD_REG_NUM         (8)  /*!< Number of I2C command registers */
 
 // FSM_RST only resets the FSM, not using it. So SOC_I2C_SUPPORT_HW_FSM_RST not defined.
 #define SOC_I2C_SUPPORT_HW_CLR_BUS  (1)