sunxi: A23/A33/H3: Actually move the secure monitor

commit 1ebfc0c6 ("sunxi: A23/A33/H3: Move sun8i secure monitor to
SRAM A2") attempted to move the secure monitor to SRAM A2. But not all
sun8i SoCs have SRAM A2, so a check was put in for SUNXI_SRAM_A2_SIZE to
avoid breaking the other SoCs.

However, because the header providing SUNXI_SRAM_A2_SIZE was not
included, this unintentionally skipped the new definitions on all SoCs.
Fix this by including the right header.

Fixes: 1ebfc0c6 ("sunxi: A23/A33/H3: Move sun8i secure monitor to SRAM A2")
Signed-off-by: Samuel Holland <samuel@sholland.org>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>