MIPS: remove .MIPS.abiflags section

The abiflags data is only used to communicate ABI information to a
program loader -- you can see what info is stored with readelf -A.
Dropping it shaves 24 bytes off of every binary (including plugins).

Change-Id: Iae78eeffe5c840ff67717707fb94821d24aac8ec

apps/plugins/plugin.lds

@@ -299,6 +299,7 @@ SECTIONS
     {
         *(.eh_frame)
 #ifdef CPU_MIPS
+        *(.MIPS.abiflags)
         *(.rel.dyn)
 #endif
     }