stm32h7: rename startup code .init.text section to .init

Do this for compatibility with INIT_ATTR, which uses the
.init section.

Change-Id: I473c29e3d38e5d5a563c98fc910d725024072735

firmware/target/arm/stm32/app.lds

@@ -39,7 +39,7 @@ SECTIONS
     {
         loadaddress = .; /* only needed to keep ROLO happy */
 
-        *(.init.text*)
+        *(.init*)
         *(.text*)
     } > SRAM_AXI :sram_rx
 

firmware/target/arm/stm32/boot.lds

@@ -18,7 +18,7 @@ SECTIONS
     {
         KEEP(*(.vectors.arm))
         KEEP(*(.vectors.platform))
-        *(.init.text*)
+        *(.init*)
         *(.text*)
         *(.rodata*)
     } > FLASH1

firmware/target/arm/stm32/crt0-stm32h7.S

@@ -24,7 +24,7 @@
     .syntax unified
     .text
 
-    .section .init.text,"ax",%progbits
+    .section .init,"ax",%progbits
 
     .global reset_handler
     .type reset_handler, function