Drop implementation of osl_incrementInterlockedCount /
osl_decrementInterlockedCount for antique 32-bit SPARC without
cas instruction (sun4, sun4c, sun4d, sun4m).

Apparently only NetBSD and OpenBSD even support such ancient hardware at
all, the Debian SPARC port already requires sun4u hardware.

Change-Id: Ic254622ae80ad65c9f545013b68d82665474402c