debug/gdb: add option to enable/disable the IPA lib for gdbserver

gdbserver >= 7.2 comes with an optional library to use tracepoints, the
In Process Agent (IPA) library, libinproctrace.so.

Currently, we build gdbserver staticaly, but that breaks the build of
the IPA lib.

Add an option to biuld the IPA lib, but not if statically linking.

Reported-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>

 # MIPS specific config options

 ## select ARCH_SUPPORTS_32

 ## select ARCH_SUPPORTS_64 if EXPERIMENTAL

 ## select ARCH_DEFAULT_32

 ## select ARCH_USE_MMU

 ## select ARCH_SUPPORTS_BOTH_ENDIAN

 ## select ARCH_DEFAULT_BE

 ## select ARCH_SUPPORTS_WITH_ARCH

 ## select ARCH_SUPPORTS_WITH_TUNE

 ## select ARCH_SUPPORTS_WITH_FLOAT

 ##

 ## help The MIPS architecture, as defined by:

 ## help     http://www.mips.com/