feat(arch): Add armv8i (32-bit ARM/AArch32) architecture & complete TUI configurator

- Support ARMv8i / ARM32 (AArch32) baremetal target with arm-linux-gnueabihf toolchain
- Implement ARMv8i boot entry point, banked exception mode stacks (IRQ, ABT, UND, SVC)
- Implement 8 exception vectors, GICv2 distributor/CPU interface, CP15 Generic Timer (100 Hz), flat Section MMU
- Support PL011 UART for early console & interactive LazyBox TTY input
- Update Makefile with make armv8i_defconfig and automated cross-compilation
- Update scripts/kconfig/menuconfig.py with dedicated armv8i options

include/arch/armv8i/mmu.h

@@ -0,0 +1,20 @@
+#ifndef _ARCH_ARMV8I_MMU_H
+#define _ARCH_ARMV8I_MMU_H
+
+#include <stdint.h>
+
+// VMSAv7 1MB Section Descriptor Flags
+#define SECTION_TYPE_MASK      (3 << 0)
+#define SECTION_TYPE_FAULT     (0 << 0)
+#define SECTION_TYPE_SECTION   (2 << 0)
+#define SECTION_BUFFERABLE     (1 << 2)
+#define SECTION_CACHEABLE      (1 << 3)
+#define SECTION_AP_RW_ALL      (3 << 10)
+#define SECTION_TEX_DEVICE     (0 << 12)
+#define SECTION_TEX_NORMAL     (1 << 12)
+#define SECTION_SHAREABLE      (1 << 16)
+#define SECTION_NON_GLOBAL     (1 << 17)
+
+void armv8i_mmu_init(void);
+
+#endif // _ARCH_ARMV8I_MMU_H