pinmux: Allow up to 6 functions

According to the "ESP32 Technical Reference Manual", the ESP32 SoC
series supports up to 6 functions per GPIO pin.  Add PINMUX_FUNC_E and
PINMUX_FUNC_F.

Jira: ZEP-2297
Signed-off-by: Leandro Pereira <leandro.pereira@intel.com>
1 file changed