Boards: st: nucleo_f302r8: fix documentation information


Fix Flash size memory for nucleo_f302r8 board

Signed-off-by: Fabrice DJIATSA <fabrice.djiatsa-ext@st.com>
diff --git a/boards/st/nucleo_f302r8/doc/index.rst b/boards/st/nucleo_f302r8/doc/index.rst
index 88afebe..7e3ce41 100644
--- a/boards/st/nucleo_f302r8/doc/index.rst
+++ b/boards/st/nucleo_f302r8/doc/index.rst
@@ -43,7 +43,7 @@
 - ARM |reg| 32-bit Cortex |reg| -M4 CPU with FPU
 - 72 MHz max CPU frequency
 - VDD from 2.0 V to 3.6 V
-- 64 MB Flash
+- 64 KB Flash
 - 16 KB SRAM
 - RTC
 - Advanced-control Timer