ARM: dove: mark 'putc' as inline

This can cause a randconfig warning without the 'inline' flag
that every other platform uses:

In file included from arch/arm/boot/compressed/misc.c:29:
arch/arm/mach-dove/include/mach/uncompress.h:14:13: error: 'putc' defined but not used [-Werror=unused-function]
   14 | static void putc(const char c)
      |             ^~~~

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20210927095343.1015422-1-arnd@kernel.org

'
Signed-off-by: Arnd Bergmann <arnd@arndb.de>