kconfig: move CONFIG_USE_PRIVATE_LIBGCC to Kconfig

kconfig: move CONFIG_USE_PRIVATE_LIBGCC to Kconfig

The private libgcc is supported only on ARM, MIPS, PowerPC, SH, x86.
Those architectures should "select" HAVE_PRIVATE_LIBGCC and
CONFIG_USE_PRIVATE_LIBGCC should depend on it.

Currently, this option is enabled on Tegra boards and x86 architecture.
Move the definition from header files to Kconfig.

Signed-off-by: Masahiro Yamada <[email protected]>
Tested-by: Simon Glass <[email protected]>
Acked-by: Simon Glass <[email protected]>
Cc: Stephen Warren <[email protected]>
Cc: Tom Warren <[email protected]>