riscv: Fix default misaligned access trap

Commit d1703dc ("RISC-V: Detect unaligned vector accesses
supported") removed the default handlers for handle_misaligned_load()
and handle_misaligned_store(). When the kernel is compiled without
RISCV_SCALAR_MISALIGNED, these handlers are never defined, causing
compilation errors.

Signed-off-by: Charlie Jenkins <charlie@rivosinc.com>
Fixes: d1703dc ("RISC-V: Detect unaligned vector accesses supported")
Reviewed-by: Jesse Taube <mr.bossman075@gmail.com>
Link: https://lore.kernel.org/r/20241108-fix_handle_misaligned_load-v2-1-91d547ce64db@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

Author: charlie-rivos

arch/riscv/include/asm/entry-common.h

@@ -25,7 +25,19 @@ static inline void arch_exit_to_user_mode_prepare(struct pt_regs *regs,
 void handle_page_fault(struct pt_regs *regs);
 void handle_break(struct pt_regs *regs);
 
+#ifdef CONFIG_RISCV_MISALIGNED
 int handle_misaligned_load(struct pt_regs *regs);
 int handle_misaligned_store(struct pt_regs *regs);
+#else
+static inline int handle_misaligned_load(struct pt_regs *regs)
+{
+	return -1;
+}
+
+static inline int handle_misaligned_store(struct pt_regs *regs)
+{
+	return -1;
+}
+#endif
 
 #endif /* _ASM_RISCV_ENTRY_COMMON_H */