Fix the flash length to use all of 256K part.

Author: pi-anl

targets/TARGET_NORDIC/TARGET_NRF5x/TARGET_NRF51/TARGET_MCU_NRF51822_UNIFIED/device/TOOLCHAIN_GCC_ARM/TARGET_MCU_NRF51_16K_S130/NRF51822.ld

@@ -2,7 +2,7 @@
 
 MEMORY
 {
-  FLASH (rx) : ORIGIN = 0x0001B000, LENGTH = 0x24000
+  FLASH (rx) : ORIGIN = 0x0001B000, LENGTH = 0x25000
   RAM (rwx) :  ORIGIN = 0x20002ef8, LENGTH = 0x1108
 }