[gd32/arm/libraries]: correct pin number in drv_gpio.c; fix compile error if use rtc in gd32 f1~f4 (#6172)

* [gd32/libraries]: fix compile error in rtc: "pmu_backup_write_enable" was not found.

* [gd32/arm/libraries/gd32_drivers/drv_gpio.c] correct gpio number.

bsp/gd32/arm/libraries/GD32F20x_Firmware_Library/SConscript

@@ -37,6 +37,7 @@ if GetDepend(['RT_USING_DAC']):
 
 if GetDepend(['RT_USING_RTC']):
     src += ['GD32F20x_standard_peripheral/Source/gd32f20x_rtc.c']
+    src += ['GD32F20x_standard_peripheral/Source/gd32f20x_pmu.c']
 
 if GetDepend(['RT_USING_WDT']):
     src += ['GD32F20x_standard_peripheral/Source/gd32f20x_wwdgt.c']

bsp/gd32/arm/libraries/GD32F30x_Firmware_Library/SConscript

@@ -37,6 +37,7 @@ if GetDepend(['RT_USING_DAC']):
 
 if GetDepend(['RT_USING_RTC']):
     src += ['GD32F30x_standard_peripheral/Source/gd32f30x_rtc.c']
+    src += ['GD32F30x_standard_peripheral/Source/gd32f30x_pmu.c']
 
 if GetDepend(['RT_USING_WDT']):
     src += ['GD32F30x_standard_peripheral/Source/gd32f30x_wwdgt.c']

bsp/gd32/arm/libraries/GD32F4xx_Firmware_Library/SConscript

@@ -38,6 +38,7 @@ if GetDepend(['RT_USING_DAC']):
 
 if GetDepend(['RT_USING_RTC']):
     src += ['GD32F4xx_standard_peripheral/Source/gd32f4xx_rtc.c']
+    src += ['GD32F4xx_standard_peripheral/Source/gd32f4xx_pmu.c']
 
 if GetDepend(['RT_USING_WDT']):
     src += ['GD32F4xx_standard_peripheral/Source/gd32f4xx_wwdgt.c']

bsp/gd32/arm/libraries/gd32_drivers/drv_gpio.c

@@ -50,7 +50,7 @@ static const struct pin_index pins[] =
     GD32_PIN(26, B, 10),
     GD32_PIN(27, B, 11),
     GD32_PIN(28, B, 12),
-    GD32_PIN(39, B, 13),
+    GD32_PIN(29, B, 13),
     GD32_PIN(30, B, 14),
     GD32_PIN(31, B, 15),
 #endif