soc/amd/cezanne/psp_verstage/uart: Fix off by 1 error

FCH_UART_ID_MAX == 2, and there are 2 UARTS, so we don't need the -1.

BUG=b:215599230
TEST=Build guybrush

Found-by: Coverity CID 1469611
Signed-off-by: Raul E Rangel <rrangel@chromium.org>
Change-Id: I5f0171ed2d3da7f86ba3cfd0457f60d2d5722625
Reviewed-on: https://review.coreboot.org/c/coreboot/+/61869
Reviewed-by: Felix Held <felix-coreboot@felixheld.de>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/soc/amd/cezanne/psp_verstage/uart.c

@@ -4,7 +4,7 @@
 #include <amdblocks/uart.h>
 #include <types.h>
 
-static void *uart_bars[FCH_UART_ID_MAX - 1];
+static void *uart_bars[FCH_UART_ID_MAX];
 
 uintptr_t get_uart_base(unsigned int idx)
 {