ANDROID: declare sp_in_global outside of CONFIG_FRAME_POINTER

Fix for riscv allmodconfig builds. Need sp_in_global to be declared
outside of #ifdef CONFIG_FRAME_POINTER to cover all cases

Fixes: f06e9ec9 ("BACKPORT: RISC-V: Stop relying on GCC's register allocator's hueristics")
Signed-off-by: Todd Kjos <tkjos@google.com>
Change-Id: Ifeb8901498895bb2079d9541e856b417619a6b78