scripts: genpinctrl: fix xspim regex

Fixes the regex used to generate XSPIM pins:
* NCS pins are numbered 1-2 instead of 0-1
* Expand IO numbers beyond 7 (necessary for STM32N6)

Signed-off-by: Guillaume Gautier <guillaume.gautier-ext@st.com>

scripts/genpinctrl/stm32-pinctrl-config.yaml

@@ -223,7 +223,7 @@
   slew-rate: very-high-speed
 
 - name: XSPIM
-  match: "^XSPIM(.*)(?:CLK|NCS[0-1]|DQS[0-1]|IO[0-7])$"
+  match: "^XSPIM(.*)(?:CLK|NCS[1-2]|DQS[0-1]|IO\\d+)$"
   slew-rate: very-high-speed
 
 - name: SDMMC