meson: install schemas in a new directory

schemas need to be in a different directory than configurations for EM
to be able to recursively find configurations without edge-cases.

The new path makes more sense since it is the same relative path as in
the EM repository.

Tested: on Tyan s8030 board. Schemas are installed as expected.

```
ls /usr/share/entity-manager/configurations/schemas/
... no output
ls /usr/share/entity-manager/schemas/
cpld.json                  intel.json                 pid.json
exposes_record.json        leak_detector.json         pid_zone.json
firmware.json              legacy.json                satellite_controller.json
global.json                mctp.json                  stepwise.json
gpio_presence.json         nvidia.json                virtual_sensor.json
ibm.json                   openbmc-dbus.json
```

The entity-manager starts as expected, no errors in log.
```
Jul 01 08:27:33 s8030-bmc-30303035c0c1 systemd[1]: Started Entity Manager.
Jul 01 08:27:45 s8030-bmc-30303035c0c1 entity-manager[1692]: Inventory Added: Supermicro PWS 920P SQ 0
Jul 01 08:27:45 s8030-bmc-30303035c0c1 entity-manager[1692]: Inventory Added: Supermicro PWS 920P SQ 1
Jul 01 08:27:45 s8030-bmc-30303035c0c1 entity-manager[1692]: Inventory Added: chassis
Jul 01 08:27:45 s8030-bmc-30303035c0c1 entity-manager[1692]: Inventory Added: MBX 1.57 Chassis
```

Change-Id: I426673067eea7908c77cbaf00dfa783d781db2c5
Signed-off-by: Alexander Hansen <alexander.hansen@9elements.com>
diff --git a/src/entity_manager/configuration.hpp b/src/entity_manager/configuration.hpp
index b3b2cdc..015f713 100644
--- a/src/entity_manager/configuration.hpp
+++ b/src/entity_manager/configuration.hpp
@@ -11,7 +11,7 @@
 constexpr const char* hostConfigurationDirectory = SYSCONF_DIR "configurations";
 constexpr const char* configurationDirectory = PACKAGE_DIR "configurations";
 constexpr const char* currentConfiguration = "/var/configuration/system.json";
-constexpr const char* schemaDirectory = PACKAGE_DIR "configurations/schemas";
+constexpr const char* schemaDirectory = PACKAGE_DIR "schemas";
 
 bool writeJsonFiles(const nlohmann::json& systemConfiguration);