arch: Changes MPU alignment to 128 when FPU_SHARING and MPU_STACK_GUARD

With our builds for Arm M7 we are selecting FPU_SHARING and
MPU_STACK_GUARD. For that setup, we have
ARM_MPU_REGION_MIN_ALIGN_AND_SIZE=64 and
MPU_STACK_GUARD_MIN_SIZE_FLOAT=128. So worst case scenario,
we are going to have stack that is 64-byte aligned and
128-byte guard at the bottom of the buffer.

Fixes: #83714

Signed-off-by: Maciej Kusio <[email protected]>

Author: rysiof

arch/arm/core/mpu/Kconfig

@@ -8,6 +8,7 @@ if CPU_HAS_MPU
 config ARM_MPU_REGION_MIN_ALIGN_AND_SIZE
 	int
 	default 256 if ARM_MPU && ARMV6_M_ARMV8_M_BASELINE && !ARMV8_M_BASELINE
+	default 128 if ARM_MPU && FPU_SHARING && MPU_STACK_GUARD
 	default 64 if ARM_MPU && AARCH32_ARMV8_R
 	default 32 if ARM_MPU
 	default 4