Kconfig: add quotes in default string value

To avoid the setconfig warning: "style: quotes recommended around
default value for string symbol"

arch/arm/src/lpc17xx_40xx/Kconfig

@@ -416,7 +416,7 @@ config LPC17_40_EEPROM
 	depends on ARCH_FAMILY_LPC177X || ARCH_FAMILY_LPC178X || ARCH_FAMILY_LPC407X || ARCH_FAMILY_LPC408X
 
 config LPC17_40_PROGMEM
-	bool PROGMEM
+	bool "PROGMEM"
 	default n
 	select ARCH_HAVE_PROGMEM
 	---help---

arch/arm/src/s32k1xx/Kconfig

@@ -329,7 +329,7 @@ config S32K1XX_RTC
 	default n
 
 config S32K1XX_PROGMEM
-    bool PROGMEM
+    bool "PROGMEM"
     default n
     select ARCH_HAVE_PROGMEM
     depends on (ARCH_CHIP_S32K11X || (ARCH_CHIP_S32K14X && !ARCH_CHIP_S32K148) )

boards/arm/sama5/giant-board/Kconfig

@@ -59,7 +59,7 @@ config SAMA5D27_SDMMC0_MOUNT
 
 config SAMA5D27_SDMMC0_MOUNT_BLKDEV
 	string "SDMMC0 block device name"
-	default mmc0
+	default "mmc0"
 	depends on SAMA5_SDMMC0
 
 config SAMA5D27_SDMMC0_MOUNT_MOUNTPOINT
@@ -97,7 +97,7 @@ config SAMA5D27_SDMMC1_MOUNT
 
 config SAMA5D27_SDMMC1_MOUNT_BLKDEV
 	string "SDMMC1 block device name"
-	default mmc1
+	default "mmc1"
 	depends on SAMA5_SDMMC1
 
 config SAMA5D27_SDMMC1_MOUNT_MOUNTPOINT

boards/arm/sama5/sama5d2-xult/Kconfig

@@ -67,7 +67,7 @@ config SAMA5D27_SDMMC0_MOUNT
 
 config SAMA5D27_SDMMC0_MOUNT_BLKDEV
     string "SDMMC0 block device name"
-    default mmc0
+    default "mmc0"
     depends on SAMA5_SDMMC0
 
 config SAMA5D27_SDMMC0_MOUNT_MOUNTPOINT
@@ -105,7 +105,7 @@ config SAMA5D27_SDMMC1_MOUNT
 
 config SAMA5D27_SDMMC1_MOUNT_BLKDEV
     string "SDMMC1 block device name"
-    default mmc1
+    default "mmc1"
     depends on SAMA5_SDMMC1
 
 config SAMA5D27_SDMMC1_MOUNT_MOUNTPOINT