soc: qcom: pdr: use static for servreg_* variables

soc: qcom: pdr: use static for servreg_* variables

Sparse reports this repesentative issue
pdr_internal.h:31:22: warning: symbol 'servreg_location_entry_ei' was not declared. Should it be static?
Similar for other servreg_*

Global variables should not be defined in header files.
This only works because pdr_internal.h is only included
by pdr_interface.c.  Single file use variables should be
static so add static to their storage-class specifiers.

Signed-off-by: Tom Rix <trix@redhat.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20220422173806.21982-1-trix@redhat.com