Add pages for esc1+shift and esc1+ctrl - some UK USB keyboards (Dell) and it seems some
German ones: https://groups.google.com/forum/#!topic/comp.os.plan9/ycok6NTCWCg seem to
generate an esc1 + code scancode combination for the pipe/backslash key. Seems like
overkill to add two whole pages for just two keys, but there again RAM is cheap these days.

Probably should take the changes across to omap/kbd.c (and by extension bcm/kbd.c)
but the changes are trivial.