freedreno: Do not link ir3_compiler with valgrind libraries.

freedreno: Do not link ir3_compiler with valgrind libraries.

This patch fixes this freedreno autotools build error.

  CXXLD    ir3_compiler
/usr/lib/valgrind/libcoregrind-amd64-linux.a(libcoregrind_amd64_linux_a-m_main.o): In function `_start':
(.text+0x0): multiple definition of `_start'
/usr/lib/gcc/x86_64-linux-gnu/7/../../../x86_64-linux-gnu/Scrt1.o:(.text+0x0): first defined here
/usr/bin/ld: /usr/lib/valgrind/libcoregrind-amd64-linux.a(libcoregrind_amd64_linux_a-m_main.o): relocation R_X86_64_32S against undefined symbol `vgPlain_interim_stack' can not be used when making a PIE object; recompile with -fPIC
/usr/bin/ld: /usr/lib/valgrind/libcoregrind-amd64-linux.a(libcoregrind_amd64_linux_a-m_trampoline.o): relocation R_X86_64_32 against `.text' can not be used when making a PIE object; recompile with -fPIC
/usr/bin/ld: /usr/lib/valgrind/libcoregrind-amd64-linux.a(libcoregrind_amd64_linux_a-dispatch-amd64-linux.o): relocation R_X86_64_32S against symbol `vgPlain_stats__n_xindirs_32' can not be used when making a PIE object; recompile with -fPIC
/usr/bin/ld: final link failed: Nonrepresentable section on output
collect2: error: ld returned 1 exit status

Fixes: f3cc0d274756 ("freedreno: import libdrm_freedreno + redesign submit")
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=108595
Signed-off-by: Vinson Lee <vlee@freedesktop.org>
Reviewed-by: Rob Clark <robdclark@gmail.com>