feat(stm32mp2): use early traces

Replace ERROR message with EARLY_ERROR for OTP driver probe, as this
will be called before default console is enabled.

Signed-off-by: Yann Gautier <yann.gautier@st.com>
Change-Id: I756a04727c494d5f681a45d47d01189dff07dbe7
diff --git a/plat/st/stm32mp2/bl2_plat_setup.c b/plat/st/stm32mp2/bl2_plat_setup.c
index a09598b..724209a 100644
--- a/plat/st/stm32mp2/bl2_plat_setup.c
+++ b/plat/st/stm32mp2/bl2_plat_setup.c
@@ -27,7 +27,7 @@
 void bl2_el3_plat_arch_setup(void)
 {
 	if (stm32_otp_probe() != 0U) {
-		ERROR("OTP probe failed\n");
+		EARLY_ERROR("OTP probe failed\n");
 		panic();
 	}
 }