ARM: pxa: remove sharpsl_fatal_check function

The sharpsl_fatal_check has not been used since Pavel Machek removed
the caller in 99f329a2

 "pxa/sharpsl_pm: zaurus c3000 aka spitz: fix
resume". Nobody has complained since 2009, so it's safe to assume we
can just remove the function.

Without this patch, building corgi_defconfig results in:

/home/arnd/linux-arm/arch/arm/mach-pxa/sharpsl_pm.c:693:12: warning: 'sharpsl_fatal_check' defined but not used [-Wunused-function]

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Stanislav Brabec <utx@penguin.cz>
Cc: Eric Miao <eric.y.miao@gmail.com>
Cc: Haojian Zhuang <haojian.zhuang@gmail.com>