treewide: fixup various mysql ocurrences after re-split

pkgs/development/libraries/libdbi-drivers/default.nix

@@ -26,8 +26,6 @@ stdenv.mkDerivation rec {
     "--with-dbi-libdir=${libdbi}/lib"
   ] ++ optionals (libmysql != null) [
     "--with-mysql"
-    "--with-mysql-incdir=${libmysql}/include/mysql"
-    "--with-mysql-libdir=${libmysql}/lib/mysql"
   ] ++ optionals (postgresql != null) [
     "--with-pgsql"
     "--with-pgsql_incdir=${postgresql}/include"

pkgs/development/libraries/opendbx/default.nix

@@ -1,5 +1,8 @@
 { stdenv, fetchurl, readline, mysql, postgresql, sqlite }:
 
+let
+  inherit (stdenv.lib) getDev getLib;
+in
 stdenv.mkDerivation rec {
   name = "opendbx-1.4.6";
 
@@ -9,10 +12,10 @@ stdenv.mkDerivation rec {
   };
 
   preConfigure = ''
-    export CPPFLAGS="-I${mysql.lib}/include/mysql"
-    export LDFLAGS="-L${mysql.lib}/lib/mysql"
+    export CPPFLAGS="-I${getDev mysql.client}/include/mysql"
+    export LDFLAGS="-L${getLib mysql.client}/lib/mysql -L${getLib postgresql}/lib"
     configureFlagsArray=(--with-backends="mysql pgsql sqlite3")
   '';
 
-  buildInputs = [ readline mysql.lib postgresql sqlite ];
+  buildInputs = [ readline mysql.client postgresql sqlite ];
 }

pkgs/development/libraries/qt-3/default.nix

@@ -47,7 +47,7 @@ stdenv.mkDerivation {
       -I${randrproto}/include" else "-no-xrandr"}
     ${if xineramaSupport then "-xinerama -L${libXinerama.out}/lib -I${libXinerama.dev}/include" else "-no-xinerama"}
     ${if cursorSupport then "-L${libXcursor.out}/lib -I${libXcursor.dev}/include" else ""}
-    ${if mysqlSupport then "-qt-sql-mysql -L${mysql.lib}/lib/mysql -I${mysql.lib}/include/mysql" else ""}
+    ${if mysqlSupport then "-qt-sql-mysql -L${stdenv.lib.getLib mysql.client}/lib/mysql -I${mysql.client}/include/mysql" else ""}
     ${if xftSupport then "-xft
       -L${libXft.out}/lib -I${libXft.dev}/include
       -L${libXft.freetype.out}/lib -I${libXft.freetype.dev}/include