s390/ctl_reg: add union type for control register 0
s390/ctl_reg: add union type for control register 0

Add 'union ctlreg0_bits' to easily allow setting and testing bits of
control register 0 bits.
This patch only adds the bits needed for the new guest access functions.
Other bits and control registers can be added when needed.

Signed-off-by: Heiko Carstens <8dcf0f69152f32f23184f83357a3731522e56b9c@de.ibm.com>
Reviewed-by: Thomas Huth <9e65be74847981e55b2564b6266c57d86d3bac05@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <94980dd689360e06f79e918bf71ea5fed7a2bc63@de.ibm.com>
Signed-off-by: Christian Borntraeger <49712f635b03c16d7f4c43df70e49ec8c565813d@de.ibm.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs