Use correct board file in xelus/valor_frl_tkl/rev2_0 (#18071)

keyboards/xelus/valor_frl_tkl/rev2_0/rules.mk

@@ -1,6 +1,6 @@
 # MCU name
 MCU = STM32F411
-BOARD = GENERIC_STM32_F401XC
+BOARD = GENERIC_STM32_F411XE
 
 # Bootloader selection
 BOOTLOADER = stm32-dfu