UBUNTU: SAUCE: Revert "arm64/fpsimd: Make kernel_neon_ API _GPL"

Temporarily revert commmit aaeca98456 ("arm64/fpsimd: Make
kernel_neon_ API _GPL"), that is currently breaking zfs.

When zfs will be fixed we can drop this SAUCE patch.

Signed-off-by: Andrea Righi <andrea.righi@canonical.com>

arch/arm64/kernel/fpsimd.c

@@ -1923,7 +1923,7 @@ void kernel_neon_begin(void)
 
 	put_cpu_fpsimd_context();
 }
-EXPORT_SYMBOL_GPL(kernel_neon_begin);
+EXPORT_SYMBOL(kernel_neon_begin);
 
 /*
  * kernel_neon_end(): give the CPU FPSIMD registers back to the current task
@@ -1950,7 +1950,7 @@ void kernel_neon_end(void)
 	else
 		clear_thread_flag(TIF_KERNEL_FPSTATE);
 }
-EXPORT_SYMBOL_GPL(kernel_neon_end);
+EXPORT_SYMBOL(kernel_neon_end);
 
 #ifdef CONFIG_EFI