gimp: fix compile in latest environment

fixes:
ld: error: file_ico-ico-load.o: requires unsupported dynamic reloc R_ARM_THM_MOVW_ABS_NC; recompile with -fPIC
ld: error: file_ico-ico-save.o: requires unsupported dynamic reloc R_ARM_THM_MOVW_ABS_NC; recompile with -fPIC

Signed-off-by: Andreas Müller <schnitzeltony@googlemail.com>
Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>