efi_loader: use LOGC_EFI consistently

The log category should be LOGC_EFI all over the EFI sub-system.

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
diff --git a/lib/efi_loader/efi_variable_tee.c b/lib/efi_loader/efi_variable_tee.c
index 8b6b0a3..0d090d0 100644
--- a/lib/efi_loader/efi_variable_tee.c
+++ b/lib/efi_loader/efi_variable_tee.c
@@ -10,6 +10,8 @@
  *    Abdellatif El Khlifi <abdellatif.elkhlifi@arm.com>
  */
 
+#define LOG_CATEGORY LOGC_EFI
+
 #if CONFIG_IS_ENABLED(ARM_FFA_TRANSPORT)
 #include <arm_ffa.h>
 #endif