kl27z_hic: Update flash config in startup assembly files.

This porst into th GCC asm file the flash config data from the
armcc file for the micro:bit board.

The default kl27z configuration (non-micro:bit) has been updated in
both GCC and armcc to have the FOPT config disable NMI interrupts
and ensure the BOOTCFG0 pin doesn't force the ROM bootloader to
run on startup.

source/hic_hal/freescale/kl27z/armcc/startup_MKL27Z4.s

@@ -276,7 +276,11 @@ FPROT0          EQU     nFPROT0:EOR:0xFF
 ;       <2=> Boot from ROM
 ;       <3=> Boot from ROM
 ;         <i> Boot source selection
+#if defined(MICROBIT_LOCK_BOOTLOADER)
 FOPT          EQU     0x39
+#else
+FOPT          EQU     0x3B
+#endif
 ;   </h>
 ;   <h> Flash security byte (FSEC)
 ;     <i> WARNING: If SEC field is configured as "MCU security status is secure" and MEEN field is configured as "Mass erase is disabled",

source/hic_hal/freescale/kl27z/gcc/startup_MKL27Z4.S

@@ -83,15 +83,53 @@ __isr_vector:
 /* Flash Configuration */
     .section .FlashConfig, "a"
 #if defined(MICROBIT_LOCK_BOOTLOADER)
+    /* Backdoor Comparison Key: "MICROBIT" */
     .long 0x5243494D
     .long 0x5449424F
+    /* Program flash protection bytes (FPROT): Protect the first 32 kB of flash */
     .long 0xFFFFFFF0
-    .long 0xFFFF39FE
+    /* Flash security byte (FSEC)
+     * KEYEN  [6:7] -> 0b10 Backdoor key access enabled
+     * MEEN   [4:5] -> 0b11 Mass erase is enabled
+     * FSLACC [2:3] -> 0b11 NXP factory access granted
+     * SEC    [0:1] -> 0b10 MCU security status is unsecure
+     */
+    .byte 0xBE
+    /* Flash nonvolatile option byte (FOPT):
+     * BOOTSRC_SEL [7:6] -> 0b00 Boot from flash
+     * FAST_INIT     [5] -> 0b1 Fast Initialization
+     * RESET_PIN_CFG [3] -> 0b1 RESET_b pin is dedicated
+     * NMI_DIS       [2] -> 0b0 NMI interrupts are always blocked
+     * BOOTPIN_OPT   [1] -> 0b0 Force Boot from ROM if BOOTCFG0 asserted
+     * LPBOOT      [4:0] -> 0b11 Core and system clock divider (OUTDIV1) is 0x0 (divide by 1)
+     */
+    .byte 0x39
+    /* 2 reserved bytes */
+    .byte 0xFF, 0xFF
 #else
+    /* Backdoor Comparison Key: Unset */
     .long 0xFFFFFFFF
     .long 0xFFFFFFFF
+    /* Program flash protection bytes (FPROT): None */
     .long 0xFFFFFFFF
-    .long 0xFFFF3FFE
+    /* Flash security byte (FSEC)
+     * KEYEN  [6:7] -> 0b11 Backdoor key access disabled
+     * MEEN   [4:5] -> 0b11 Mass erase is enabled
+     * FSLACC [2:3] -> 0b11 NXP factory access granted
+     * SEC    [0:1] -> 0b10 MCU security status is unsecure
+     */
+    .byte 0xFE
+    /* Flash nonvolatile option byte (FOPT):
+     * BOOTSRC_SEL [7:6] -> 0b00 Boot from flash
+     * FAST_INIT     [5] -> 0b1 Fast Initialization
+     * RESET_PIN_CFG [3] -> 0b1 RESET_b pin is dedicated
+     * NMI_DIS       [2] -> 0b0 NMI interrupts are always blocked
+     * BOOTPIN_OPT   [1] -> 0b1 Boot source configured by FOPT[7:6] (BOOTSRC_SEL) bits
+     * LPBOOT      [4:0] -> 0b11 Core and system clock divider (OUTDIV1) is 0x0 (divide by 1)
+     */
+    .byte 0x3B
+    /* 2 reserved bytes */
+    .byte 0xFF, 0xFF
 #endif
 
     .text