Kconfig: Update dependencies to avoid invalid configurations

1. Since the baud rate in the ROM cannot be changed,
   set the default baud rate of the 26Mhz version
   of esp32c2 to 74800
2. Since the systimer configuration of the 26Mhz
   version requires a non-integer systimer frequency
   configuration, and this feature is not supported
   in the current ROM, this option is disabled for
   the 26Mhz version esp32c2

components/esp_system/Kconfig

@@ -331,6 +331,7 @@ menu "ESP System Settings"
         int
         prompt "UART console baud rate" if ESP_CONSOLE_UART_CUSTOM
         depends on ESP_CONSOLE_UART
+        default 74880 if ESP32C2_XTAL_FREQ_26
         default 115200
         range 1200 4000000 if !PM_ENABLE
         range 1200 1000000 if PM_ENABLE

components/hal/Kconfig

@@ -67,7 +67,7 @@ menu "Hardware Abstraction Layer (HAL) and Low Level (LL)"
 
     config HAL_SYSTIMER_USE_ROM_IMPL
         bool "Use ROM implementation of SysTimer HAL driver"
-        depends on ESP_ROM_HAS_HAL_SYSTIMER
+        depends on ESP_ROM_HAS_HAL_SYSTIMER && !ESP32C2_XTAL_FREQ_26
         default y
         help
             Enable this flag to use HAL functions from ROM instead of ESP-IDF.