build: unused global variables in header file causing BLE build failure

factory_data.h defines 2 global variables which aren't actually used anywhere.
However, they become global symbols in any C files that include this header
file.  For most builds, this header file is included only once but, for CurieBle
library builds, it is included by another C file as well.  This causes a linker
error due to duplicate symbols in the final image.

The simple solution is to just remove these variables, because they aren't used.

Signed-off-by: Dan O'Donovan <dan@emutex.com>

Author: Dan-Lightsource

system/libarc32_arduino101/framework/include/infra/factory_data.h

@@ -54,8 +54,6 @@
 /** Key Patterns in the OTP area */
 #define PATTERN_KEY_START  0xA5A5A5A5
 #define PATTERN_KEY_END    0x5A5A5A5A
-const char INVALID_SN_F[4] = {0xFF, 0xFF, 0xFF, 0xFF};
-const char INVALID_SN_0[4] = {0,0,0,0};
 
 enum hardware_type {
     EVT = 0x00,  /*!< Engineering hardware */