[PATCH] skge: function amd macro name change

The inlines and macro's needed some cleanup's and fixes:
 * change name of macro SKGEMAC_REG to SK_REG to better reflect usage
   and fix comments
 * ditto for SK_GEXM_REG -> SK_XMAC_REG and SKGEGMA_REG -> SK_GMA_REG

 * change skge_gm_ to just gm_ since it is just a local function and long
   names look ugly.
 * change skge_xm_ to just xm_
 * fix xm_write32 to write as two u16's with correct byte order
 * fix xm_outaddr to correctly use offset

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>