ARM: 7920/1: topology: Staticise non-exported symbols

These symbols are only referenced in this source file so can be made
static, and the efficiency table is constant data so can be declared as
such.  This avoids polluting the global namespace and fixes warnings
from sparse.

The function arch_scale_freq_power() is still not prototyped or static,
this is a separate issue as this is overriding a weak symbol from the
scheduler which neglects to provide a prototype.

Change-Id: I68972ebac696a4d13d8b1f069d1d153aef2227ee
Signed-off-by: Mark Brown <broonie@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>