memory: ti-emif-sram: move driver-specific asm-offset.h to drivers/memory/

<generated/ti-emif-asm-offsets.h> is only generated and included
by drivers/memory/, so it does not need to reside in the globally
visible include/generated/.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Santosh Shilimkar <ssantosh@kernel.org>