Drop automatic inclusion of .pc file for baselibs.

Fixes openSUSE#724.

Avoid default inclusion of pkgconfig files in automatically generated
baselibs configured biarch packages. This avoids the "have choice" issue
seen with `BuildRequires: pkgconfig(FOO)` type dependencies on OBS for
any dependents of a biarch FOO-devel package. It is wrong to ask every
project supporting biarch devel packages to configure project macros to
disfavour one pkgconfig based dependency in favour of another.

Packager may at their wish explicitly include the pkgconfig file in the
biarch package explicitly by appropriately configure the associated
baselibs.conf file, but as a default, this should be hardly ever
required.

baselibs_configs/baselibs_global.conf

@@ -24,7 +24,7 @@ targettype 64bit extension 64
 
 targetname <name>-<targettype>
 
-+.*/lib(64|ilp32)?/.*\.(so\..*|so|o|a|la|pc)$
++.*/lib(64|ilp32)?/.*\.(so\..*|so|o|a|la)$
 
 targettype 64bit -^(/usr)?/lib(ilp32)?/lib
 targettype 32bit -/lib64/