Update boards.txt

Co-authored-by: Frederic Pillon <frederic.pillon@st.com>
Signed-off-by: Aurentiaco35 <140486360+Aurentiaco35@users.noreply.github.com>

Author: Aurentiaco35

boards.txt

@@ -8010,7 +8010,7 @@ GenH7.menu.pnum.GENERIC_H7B0VBTX.build.variant=STM32H7xx/H7A3V(G-I)(H-T)_H7B0VBT
 # Generic H7B3VIHx
 GenH7.menu.pnum.GENERIC_H7B3VIHX=Generic H7B3VIHx
 GenH7.menu.pnum.GENERIC_H7B3VIHX.upload.maximum_size=2097152
-GenH7.menu.pnum.GENERIC_H7B3VIHX.upload.maximum_data_size=1458176
+GenH7.menu.pnum.GENERIC_H7B3VIHX.upload.maximum_data_size=1048576
 GenH7.menu.pnum.GENERIC_H7B3VIHX.build.board=GENERIC_H7B3VIHX
 GenH7.menu.pnum.GENERIC_H7B3VIHX.build.product_line=STM32H7B3xx
 GenH7.menu.pnum.GENERIC_H7B3VIHX.build.variant=STM32H7xx/H7A3V(G-I)(H-T)_H7B0VBT_H7B3VI(H-T)