arm: testsuite: improve compatibility of gcc.target/arm/pr59575.c

Use dg-require-effective-target/dg-add-options to improve
compatibility of this test with various compiler configurations.

gcc/testsuite:

	* gcc.target/arm/pr59575.c: Use dg-require-effective-target and
	dg-add-options.

gcc/testsuite/gcc.target/arm/pr59575.c

 /* PR target/59575 */
 /* { dg-do compile } */
+/* { dg-require-effective-target arm_arch_v7a_ok } */
 /* { dg-skip-if "-mpure-code supports M-profile only" { *-*-* } { "-mpure-code" } } */
-/* { dg-options "-Os -g -march=armv7-a" } */
+/* { dg-options "-Os -g" } */
+/* { dg-add-options arm_arch_v7a } */
 
 void foo (int *);
 int *bar (int, long long, int);