peripheral clock gating register
| SPI01_CLK_EN | Set 1 to enable SPI01 clock |
| UART_CLK_EN | Set 1 to enable UART clock |
| UART1_CLK_EN | Set 1 to enable UART1 clock |
| SPI2_CLK_EN | Set 1 to enable SPI2 clock |
| I2C_EXT0_CLK_EN | Set 1 to enable I2C_EXT0 clock |
| LEDC_CLK_EN | Set 1 to enable LEDC clock |
| TIMERGROUP_CLK_EN | Set 1 to enable TIMERGROUP clock |
| UART_MEM_CLK_EN | Set 1 to enable UART_MEM clock |
| APB_SARADC_CLK_EN | Set 1 to enable APB_SARADC clock |
| SYSTIMER_CLK_EN | Set 1 to enable SYSTEMTIMER clock |
| ADC2_ARB_CLK_EN | Set 1 to enable ADC2_ARB clock |