ath79: kernel: Add missing quote to drivers/mfd/Kconfig

A missing quote in target/linux/ath79/patches-5.x/920-mikrotik-rb4xx.patch
produces:

...
scripts/kconfig/conf  --syncconfig Kconfig
drivers/mfd/Kconfig:2016:warning: multi-line strings not supported
...

This patch adds missing closing quote, fixing the above warning.

Signed-off-by: Paul Blazejowski <[email protected]>

target/linux/ath79/patches-5.10/920-mikrotik-rb4xx.patch

@@ -5,7 +5,7 @@
  	  device found on several devices in RAVE line of hardware.
  
 +config MFD_RB4XX_CPLD
-+	tristate "CPLD driver for Mikrotik RB4xx series boards
++	tristate "CPLD driver for Mikrotik RB4xx series boards"
 +	select MFD_CORE
 +	depends on ATH79 || COMPILE_TEST
 +	help

target/linux/ath79/patches-5.4/920-mikrotik-rb4xx.patch

@@ -5,7 +5,7 @@
  	  device found on several devices in RAVE line of hardware.
  
 +config MFD_RB4XX_CPLD
-+	tristate "CPLD driver for Mikrotik RB4xx series boards
++	tristate "CPLD driver for Mikrotik RB4xx series boards"
 +	select MFD_CORE
 +	depends on ATH79 || COMPILE_TEST
 +	help