ARM: efm32: drop unused file entry-macro.S

This file is unused since commit

	e6d159cd (ARM: 7890/1: v7-M: drop using mach/entry-macro.S)

which went into v3.14-rc1.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>

arch/arm/mach-efm32/include/mach/entry-macro.S

-/*
- * Empty file waiting for deletion once <mach/entry-macro.S> isn't needed any
- * more. Patch "ARM: v7-M: drop using mach/entry-macro.S" sitting in next.
- */