Merge bitcoin-core/secp256k1#1441: asm: add .note.GNU-stack section f…

…or non-exec stack

33dc7e4 asm: add .note.GNU-stack section for non-exec stack (fanquake)

Pull request description:

  With this in place, we no-longer see warnings like the following:
  ```bash
  /usr/lib/gcc-cross/arm-linux-gnueabihf/12/../../../../arm-linux-gnueabihf/bin/ld: warning: field_10x26_arm.o: missing .note.GNU-stack section implies executable stack
  /usr/lib/gcc-cross/arm-linux-gnueabihf/12/../../../../arm-linux-gnueabihf/bin/ld: NOTE: This behaviour is deprecated and will be removed in a future version of the linker
  ```

  Should close #1434.

ACKs for top commit:
  sipa:
    utACK 33dc7e4
  real-or-random:
    utACK 33dc7e4

Tree-SHA512: f75ded8d971f54d1e871bcc4d815ba367b3e154eea2f18309ecaf9053e22f986bfffcf28418367f8055b65a5a0b245fee045adfcb63a2196df5e2f3aa6c97b89

src/asm/field_10x26_arm.s

@@ -913,3 +913,4 @@ secp256k1_fe_sqr_inner:
 	ldmfd	sp!, {r4, r5, r6, r7, r8, r9, r10, r11, pc}
 	.size	secp256k1_fe_sqr_inner, .-secp256k1_fe_sqr_inner
 
+	.section .note.GNU-stack,"",%progbits