Kconfig: j721s2: Fix the scratchpad base

Fix the regression that occurred during the alignment of binman series
merges along with these HS fixes that caused silent regression in this.

Fixes: 30a7ee87 ("Kconfig: j721s2: Change K3_MCU_SCRATCHPAD_BASE to non firewalled region")

Signed-off-by: Manorit Chawdhry <m-chawdhry@ti.com>